Craig formulates his version of the argument as follows:
Everything that begins to exist has a cause of its existence.[b]
The universe began to exist.
Therefore, the universe has a cause of its existence."
Craig's defense of the argument mainly focuses on the second premise, and he offers several arguments to support it. For example, Craig appeals to Hilbert's example of an infinite hotel to argue that actually infinite collections are impossible, and thus the past is finite and has a beginning. And, in another argument, Craig says that the series of events in time is formed by a process in which each moment is added to history in succession. According to Craig, this process can never produce an actually infinite collection of events, but instead produces only a potentially infinite one. On this basis, he argues that the past is finite and has a beginning.
The Kalam argument concludes that the universe had a cause, but Craig further argues that the cause must be a person. First, he says that the cause of the universe is outside of time, as it causes the beginning of time itself. He then says that causes that are outside of time only have eternal effects if they are non-personal. Given his acceptance of the Kalam argument for a non-eternal universe, he concludes that the cause of the universe must be personal.
Craig is a proponent of Molinism, an idea first formulated by the Jesuit theologian Luis de Molina according to which God possesses foreknowledge of which free actions each person would perform under every possible circumstance, a kind of knowledge that is sometimes termed "middle knowledge." Protestant-Molinism, such as Craig's, first entered Protestant theology through two anti-Calvinist thinkers: Jacobus Arminius and Conrad Vorstius. Molinists such as Craig appeal to this idea to reconcile the perceived conflict between God's providence and foreknowledge with human free will. The idea is that, by relying on middle knowledge, God does not interfere with anyone's free will, instead choosing which circumstances to actualize given a complete understanding of how people will freely choose to act in response. Craig also appeals to Molinism in his discussions of the inspiration of scripture, Christian exclusivism, the perseverance of the Saints, and missionary evangelism.
Philosophy of time
Craig defends a presentist version of the A-theory of time. According to this theory, the present exists, but the past and future do not. Additionally, he holds that there are tensed facts, such as it is now lunchtime, which cannot be reduced to or identified with tenseless facts of the form it is lunchtime at noon on February 10, 2020. According to this theory, presentness is a real aspect of time, and not merely a projection of our thought and talk about time. He raises several defenses of this theory, two of which are especially notable. First, he criticizes J. M. E. McTaggart's argument that the A-theory is incoherent, suggesting that McTaggart's argument begs the question by covertly presupposing the B-theory. Second, he defends the A-theory from empirical challenges arising from the standard interpretation of Einstein's Special Theory of Relativity (SR). He responds to this challenge by advocating a neo-Lorentzian interpretation of SR which is empirically equivalent to the standard interpretation, and which is consistent with the A-theory and with absolute simultaneity. Craig criticizes the standard physical-world interpretation of SR on the grounds that it is based on a discredited positivist epistemology. Moreover, he claims that positivism is inconsistent with the appeal to SR made by these opponents of the A-theory.
Craig argues that God existed in a timeless state causally prior to creation, but has existed in a temporal state beginning with creation, by virtue of his relationship with tensed facts and his interactions with events.. He gives two arguments in support of that view. First, he says that, given his tensed view of time, God cannot be timeless once he has created a temporal universe, since, after that point, he is related to time through his interactions and through causing events in time. Second, Craig says that as a feature of his omniscience, God must know the truth related to tensed facts about the world, such as whether the statement "Today is January 15th" is true or not or what is happening right now.[c]
Resurrection of Jesus
Craig has written two volumes arguing for the historicity of the resurrection of Jesus, The Historical Argument for the Resurrection of Jesus (1985) and Assessing the New Testament Evidence for the Historicity of the Resurrection of Jesus (3rd ed., 2002). In the former volume, Craig describes the history of the discussion, including David Hume's arguments against the identification of miracles. The latter volume is an exegetical study of the New Testament material pertinent to the resurrection.
Craig structures his arguments for the historicity of the resurrection under 3 headings:
Various individuals and groups experienced appearances of Jesus alive after his death.
The earliest disciples came to believe that God had raised Jesus from the dead despite strong predispositions to the contrary.
Craig argues that the best explanation of these three events is a literal resurrection  He applies an evaluative framework developed by philosopher of history C. Behan McCullagh to examine various theoretical explanations proposed for these events. From that frame work, he rejects alternative theories such as Gerd Lüdemann's hallucination hypothesis, the conspiracy hypothesis, and Heinrich Paulus or Friedrich Schleiermacher’s apparent death hypothesis as lacking explanatory scope, explanatory power, and sufficient historical knowledge.
Craig favors a more neutral interpretation of the use of concepts like formal quantifiers of first-order logic where a statement can be true, even if there isn’t an object it is referencing. Craig gives the example of the statement “the price of the ticket is ten dollars” which he argues can still be a true statement even if there isn’t an actual object called a “price.”  He defines these references as a speech act rather than a word-world relation, so that singular terms may be used in true sentences without commitment to corresponding objects in the world. Craig has additionally argued that even if one were to grant that these references were being used as in a word-world relation, that fictionalism is a more coherent explanation of their use; in particular pretense theory, according to which statements about abstract objects are expressions of make-believe, imagined to be true, though literally false.
Craig has also proposed a neo-Apollinarian Christology in which the divine logos stands in for the human soul of Christ and completes his human nature.
According to Nathan Schneider, "[many] professional philosophers know about him only vaguely, but in the field of philosophy of religion, [Craig's] books and articles are among the most cited". Fellow philosopher Quentin Smith writes that "William Lane Craig is one the leading philosophers of religion and one of the leading philosophers of time." In 2016, The Best Schools named William Lane Craig among the 50 most influential living philosophers.
With respect to his debating skills, Sam Harris once described Craig as "the one Christian Apologist who seems to have put the fear of God into many of my fellow atheists".
^Craig's own version of the Kalām argument is succinct: 1. 'Everything that begins to exist has a cause of its existence.' 2. 'The universe began to exist,' i.e., the temporal regress of events is finite. 3. 'Therefore the universe has a cause of its existence' Following Ghazali, Craig argues that this cause must be a personal will. Nothing but the arbitrary choice of a free agent could account for the fact that the world was created at one time rather than another, or (if time comes into being with the first event) for the fact that the first event did not have a predecessor.
^In his later work, Craig prefers to use a more specific version of the first premise; as he puts it: "Suffice it to say that I now prefer to reformulate the causal premise: 'If the universe began to exist, then the universe has a cause of its beginning.'[full citation needed]
^When Craig says that God is timeless "prior to" the creation of time, the relevant notion of priority is not supposed to be temporal, as there is no time temporally prior to the first moment of time. Rather, Craig means to suggest that God is prior to time in some non-temporal sense that is difficult to specify, and which involves the idea that God was the cause of the universe. Several philosophers have argued that Craig's notion of non-temporal priority is not clear.
^Schneider, Nathan (1 July 2013). "The New Theist". The Chronicle of Higher Education. Retrieved 11 June 2019. The result is a person [Craig] ... who cannot only hold his own against fellow analytic philosophers...
^Reichenbach, Bruce. "Cosmological Argument". Stanford Encyclopedia of Philosophy. Center for the Study of Language and Information (CSLI), Stanford University. Retrieved 12 June 2019. In his widely discussed writings William Lane Craig marshals multidisciplinary evidence for the truth of the premises found in the kalām argument.... [much more discussion follows]
^Horn, Trent (17 July 2013). "New Support for the Cosmological Argument". catholic.com. Retrieved 12 June 2019. Although the argument fell into relatively obscurity after it was promoted in the Middle Ages, it received new life through William Lane Craig’s 1979 book The Kalam Cosmological Argument. Craig has become the argument’s leading proponent, and thanks to his famous debates with atheists that end up on YouTube, the kalam argument has become well-known and is vigorously dissected by critics.
^Craig, William Lane (February 5, 2018). "Questions on Certainty and Debate". Retrieved 22 July 2019. But that doesn't undermine my knowledge that I was born in Peoria, Illinois and raised in Keokuk, Iowa.
^Craig, William Lane. "Debating". Reasonable Faith. Archived from the original on May 12, 2014. Retrieved May 8, 2014.
^Craig, William Lane (November 5, 2007). "Faith and Doubt". Retrieved 10 July 2019. To speak personally, I myself was not raised in an evangelical home, but I became a Christian my third year of high school.
^Cramer, David C. "John Hick (1922—2012)". Internet Encyclopedia of Philosophy. ISSN2161-0002. Retrieved 12 June 2019. Many of [Hick's] former students are now established Christian philosophers in their own right, including ... William Lane Craig...
^ ab"Humboldt Network: Prof. Dr. William L. Craig". Alexander von Humboldt Foundation. Alexander von Humboldt-Stiftung/Foundation. Retrieved 16 July 2019. Host(s) and host institute(s) during Humboldt sponsorship: Prof. Dr. Wolfhart Pannenberg, Ludwig-Maximilians-Universität München, München; Start of first sponsorship: 01.01.1978
^Sanders, Fred (18 September 2014). "The Strange Legacy of Theologian Wolfhart Pannenberg". Christianity Today. Archived from the original on 21 September 2014. Retrieved 12 June 2019. Accordingly, Pannenberg marshaled the available evidence and argued that the most rational interpretation of it is that Christ actually rose from the dead. That a high-level German theologian would defend Christ’s resurrection as a knowable fact was headline news in the religious press of the 1970s. It’s no surprise, then, that Pannenberg’s emphasis on the historical reliability of the Resurrection attracted students like apologist William Lane Craig.
^"The historical argument for the Resurrection of Jesus during the Deist controversy". Online Computer Library Center. OCLC925034139. Cite journal requires |journal= (help)
^Pearson, Samuel C. (Oct 1988). "Book Review: The Historical Argument for the Resurrection of Jesus during the Deist Controversy. William L. Craig". The Journal of Religion. The University of Chicago Press. 68 (4): 595. doi:10.1086/487941. In this large study, which apparently grew out of a dissertation prepared under the supervision of Wolfhart Pannenberg...
^"William Lane Craig Named TEDS Alumnus of the Year". Trinity International University. Retrieved 12 June 2019. Craig earned master’s degrees from TEDS in philosophy of religion, as well as in church history and the history of Christian thought. He taught philosophy of religion at TEDS from 1980–1986.
^ abCraig, William Lane (April 5, 2010). "#155 Debating". Reasonable Faith. Retrieved 31 July 2019. But in 1982, with my doctoral studies behind me, I received an invitation from a Canadian Christian group to debate the atheist philosopher Kai Nielsen at the University of Calgary.
^ abCraig, William Lane (2000). "Author Bio". The Only Wise God: The Compatibility of Divine Foreknowledge & Human Freedom (Reprint edition (January 2000) ed.). Wipf and Stock. ISBN978-1579103163. From 1980 to 1986 he taught philosophy of religion at Trinity, during which time he and Jan started their family. In 1987 they moved to Brussels, Belgium, where Dr. Craig pursued research at the University of Louvain until 1994.
^"Contributors". International Philosophical Quarterly. Fordham University Press. 33: 142. 1993. William Lane Craig is a visiting scholar at the Inst. Supérieur de Philosophie at the Catholic Univ. of Louvain (B-3000 Louvain-la-Neuve, Belgium), PhD from Univ. of Birmingham (Eng.) and DTh from the Univ. of Munich, he taught at Westmont College and is a Fellow of the Alexander von Humboldt Siftung. Interested in Philosophy of Religion and of Space and Time, he includes in his publications the books The Kalam Cosmological Argument and Divine Foreknowledge and Human Freedom.
^ abKristof, Nicholas (21 Dec 2018). "Professor, Was Jesus Really Born to a Virgin?". The New York Times. The New York Times Company. p. SR23. Retrieved 12 June 2019. Here’s my interview of William Lane Craig, professor of philosophy at Talbot School of Theology and Houston Baptist University.
^Quinn, Philip I. (2003). "God, Existence Of". In van Huyssteen, J Wentzel Vrede (ed.). Encyclopedia of Science and Religion. Thomson-Gale. pp. 381–382. ISBN9780028657042.
^McGrath, Alister E. (2009). Science and Religion: A New Introduction. John Wiley & Sons. ISBN9781405187909. This form of the kalam argument has been widely debated in recent years. One of its most signficant defenders has been William Lane Craig...
^Beyond Dordt and 'De Auxiliis' : the dynamics of Protestant and Catholic soteriology in the sixteenth and seventeenth centuries. Ballor, Jordan J. (Jordan Joseph),, Gaetano, Matthew T., Sytsma, David S. Leiden: Brill. 2019. pp. 103–26, 148–68. ISBN978-90-04-37711-0. OCLC1107692846.CS1 maint: others (link)
^ abQuarum, Merrit (2003). "Review: Time and Eternity: Exploring God's Relationship to Time". Journal of the Evangelical Theological Society. 46 (4): 746–749.
^ abHelm, Paul (2014). Zalta, Edward N. (ed.). "Eternity". The Stanford Encyclopedia of Philosophy. Center for the Study of Language and Information (CSLI), Stanford University (Spring 2014 Edition). ISSN1095-5054. Retrieved 15 June 2019.
^Craig, William Lane. "A Christian Perspective on Homosexuality". Reasonable Faith. Archived from the original on December 6, 2016. Retrieved September 28, 2018. So how do you find out what God thinks? The Christian says, you look in the Bible. And the Bible tells us that God forbids homosexual acts. Therefore, they are wrong.
^"Evolutionary Creationism and the Image of God in Mankind". Reasonable Faith. Retrieved June 25, 2016. Evolutionary creationism is...the view that the current evolutionary paradigm is entirely adequate, so that the evolution of presently observed biological complexity requires no causal input from God. ... I’m not convinced that evolutionary creationism is true. It seems to me that so-called progressive creationism fits the evidence quite nicely. Progressive creationism suggests that God intervenes periodically to bring about miraculously new forms of life and then allows evolutionary change to take place with respect to those life forms.
——— (1985b). The Historial Argument for the Resurrection of Jesus During the Deist Controversy. E. Mellen Press. ISBN0889468117.CS1 maint: ref=harv (link)
——— (1986). "The Problem of Miracles: A Historical and Philosophical Perspective". In Wenham, David; Blomberg, Craig (eds.). Gospel Perspectives. 6. Sheffield, England: JSOT Press. pp. 9–40.CS1 maint: ref=harv (link)
——— (1991). "'Lest Anyone Should Fall': A Middle Knowledge Perspective on Perseverance and Apostolic Warnings". International Journal for Philosophy of Religion. 29 (2): 65–74. doi:10.1007/bf00133805. ISSN1572-8684.CS1 maint: ref=harv (link)
Craig, William Lane (2012a). "God and Abstract Objects". In Stump, J. B.; Padgett, Alan G. (eds.). The Blackwell Companion to Science and Christianity. Malden, Massachusetts: Wiley-Blackwell. pp. 441–452. doi:10.1002/9781118241455.ch38. ISBN978-1-4443-3571-2.CS1 maint: ref=harv (link)
Craig, William Lane (2014). "Anti-Platonism". In Gould, Paul M. (ed.). Beyond the Control of God? Six Views on the Problem of God and Abstract. New York: Bloomsbury Academic. pp. 113–126. ISBN978-1-62356-365-3.CS1 maint: ref=harv (link)
Craig, William Lane; Carroll, Sean (2016). God and Cosmology: William Lane Craig and Sean Carroll in Dialogue. Minneapolis, Minnesota: Fortress Press. ISBN978-1-5064-0676-3.CS1 maint: ref=harv (link)
Craig, William Lane; Moreland, J. P., eds. (2000). Naturalism: A Critical Analysis. Routledge Studies in Twentieth Century Philosophy. 6. London: Routledge. ISBN978-0-415-23524-2.CS1 maint: ref=harv (link)
Creel, Richard E. (2014). Philosophy of Religion: The Basics. Chichester, England: Wiley-Blackwell. ISBN978-1-118-61945-2.CS1 maint: ref=harv (link)
Habermas, Gary (1988). "Review of The Historical Argument for the Resurrection of Jesus During the Deist Controversy by William Lane Craig". Journal of the Evangelical Theological Society. 31 (2): 240–242. ISSN0360-8808.CS1 maint: ref=harv (link)
Morriston, Wes (2013). "Doubts About the Kalam Argument". In Moreland, J. P.; Meister, Chad; Sweis, Khaldoun A. (eds.). Debating Christian Theism. New York: Oxford University Press. pp. 20–32. ISBN978-0-19-975543-1.CS1 maint: ref=harv (link)
Morriston, Wes (2018). "Craig on the Actual Infinite". In Copan, Paul; Craig, William Lane (eds.). The Kalam Cosmological Argument. Volume 1: Philosophical Arguments for the Finitude of the Past. New York: Bloomsbury Academic. doi:10.5040/9781501330827. ISBN978-1-5013-3082-7.CS1 maint: ref=harv (link)
Robinson, Jeff; Baggett, David (2016). "Craig, William Lane (1949–)". In Shook, John R. (ed.). The Bloomsbury Encyclopedia of Philosophers in America: From 1600 to the Present. London: Bloomsbury Academic. pp. 211–214. ISBN978-1-4725-7056-7.CS1 maint: ref=harv (link)