In one sense, faith in Christianity is often discussed in terms of believing God's promises, trusting in his faithfulness, and relying on God's character and faithfulness to act. Some of the definitions in the history of Christian theology have followed the biblical formulation in Hebrews 11:1: "the assurance of things hoped for, the conviction of things not seen". As in other Abrahamic religions, it includes a belief in the existence of God, in the reality of a transcendent domain that God administers as his kingdom and in the benevolence of the will of God or God's plan for humankind.
Christianity differs from other Abrahamic religions in that it focuses on the teachings of Jesus, and on his place as the prophesied Christ. It also includes a belief in the New Covenant. According to most Christian traditions, Christian faith requires a belief in Jesus' resurrection from the dead, which he states is the plan of God the Father.
Since the Protestant Reformation the meaning of this term has been an object of major theological disagreement in Western Christianity. The differences have been largely overcome in the Joint Declaration on the Doctrine of Justification (1999).The precise understanding of the term "faith" differs among the various Christian traditions. Despite these differences, Christians generally agree that faith in Jesus lies at the core of the Christian tradition, and that such faith is required in order to be a Christian.
The word "faith", translated from the Greek πιστις (pi'stis), was primarily used in the New Testament with the Greek perfect tense and translates as a noun-verb hybrid; which is not adequately conveyed by the English noun. The verb form of pi'stis is pisteuo, which is often translated into English versions of the New Testament as 'believe'. The adjectival form, pistos, is almost always translated as 'faithful'. The New Testament writers, following the translators of the Septuagint (Greek Old Testament) rendered words in the Hebrew scriptures that concerned 'faithfulness' using pi'stis-group words. The pi'stis-group words are most appropriately translated into English by a range of words, depending on the context in which they occur. In both the New Testament and other Greek texts, pi'stis describes connections of firmness that can form between a wide variety of entities: people, traditions, practices, groups, purposes, facts or propositions. The appropriate English translation is often evident from the relationship between the two entities connected by pi'stis. The pi'stis-group words in the New Testament can thus be interpreted as relating to ideas of faithfulness, fidelity, loyalty, commitment, trust, belief, and proof. The most appropriate interpretation and translation of pi'stis-group words in the New Testament is a matter of recent controversy, particularly over the meaning of pi'stis when it is directed towards Jesus.
In the Protestant tradition, faith is generally understood to be closely associated with ideas of belief, trust, and reliance. This understanding is founded in the doctrinal statements of the Reformers. One of their confessional statements explains: "the principle acts of saving faith are accepting, receiving, and resting upon Christ alone for justification, sanctification, and eternal life." The Reformers contrasted faith with human efforts to do good works as a means of justification. This understanding of saving faith has remained within the Protestant tradition. Saving faith is generally understood in terms of a belief of, trust in, and reliance on the person of Jesus and his work of atonement accomplished through his death on the cross.
In a more everyday sense, faith is often discussed in terms of believing God's promises, trusting in his faithfulness, and relying on God's character and faithfulness to act. Yet, many Protestants stress that genuine faith is also acted on, and thus it brings about different behaviour or action and does not consist merely of mental belief, trust or confidence or outright antinomianism. Hence, having authentic 'faith in Jesus' is generally understood to lead to changes in how one thinks and lives. However, the Protestant tradition holds that these changes in character and conduct do not have any value for obtaining a positive final judgment, but that a positive final judgment depends on faith alone (sola fide).
In recent decades, scholars have researched what pi'stis meant in the social context of the New Testament writers. Several scholars who have studied the usage of pi'stis in both early Greek manuscripts and the New Testament have concluded that 'faithfulness' is the most satisfactory English translation in many instances. This recent research has prompted some to argue that New Testament faith and belief in Jesus should be understood in terms of faithfulness, loyalty, and commitment to him and his teachings, rather than in terms of belief, trust and reliance. Such an understanding of faith can be integrated well with the moral influence theory of atonement.
Hebrews 11:1: "Now faith (pi'stis) is the assurance of things hoped for, the conviction of things not seen." This passage concerning the function of faith in relation to the covenant of God is often used as a definition of faith. Υποστασις (hy-po'sta-sis), translated "assurance" here, commonly appears in ancient papyrus business documents, conveying the idea that a covenant is an exchange of assurances which guarantees the future transfer of possessions described in the contract. In view of this, James Hope Moulton and George Milligan suggest the rendering: "Faith is the title deed of things hoped for" (Vocabulary of the Greek Testament, 1963, p. 660). The Greek word e´leg-khos, rendered "conviction" in Hebrews 11:1 (ESV), conveys the idea of bringing forth evidence that demonstrates something, particularly something contrary to what appears to be the case. Thereby this evidence makes clear what has not been discerned before and so refutes what has only appeared to be the case. This evidence for conviction is so positive or powerful that it is described as faith. Christian faith, described in these terms, is not synonymous with credulity, but rather has connotations of acting in faithfulness and trust.
John 3:16: "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." This passage is often used as a standard statement of Christian faith.
Hebrews 11:6: This passage describes the meaning and the practical role of faith: "Without faith it is impossible to please [God], for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him."
John 6:28–29: When asked "What must we do to do the works God requires?" the writer has Jesus answering, "The work of God is this: to believe (pi'stis) in the one he has sent."
Galatians 5:6: "For in Christ Jesus neither circumcision nor uncircumcision counts for anything, but only faith working through love."
James 2:22: "Seest thou how faith wrought with his works, and by works was faith made perfect?"
James 2:26: "For as the body without the spirit is dead, so faith without works is dead also."
Objectively, faith is the sum of truths revealed by God in Scripture and tradition and which the Church presents in a brief form in its creeds. Subjectively, faith stands for the habit or virtue by which these truths are assented to.
According to Thomas Aquinas, faith is "the act of the intellect assenting to a Divine truth owing to the movement of the will, which is itself moved by the grace of God" (St. Thomas, II-II, Q. iv, a. 2). And just as the light of faith is a gift supernaturally bestowed upon the understanding, so also this Divine grace moving the will is, as its name implies, an equally supernatural and an absolutely gratuitous gift. Neither gift is due to previous study, neither of them can be acquired by human efforts, but "Ask and ye shall receive." Because the virtue is "infused" and not reachable by human efforts, it is therefore one of the theological virtues.
"We believe", says the Vatican Council (III, iii), "that revelation is true, not indeed because the intrinsic truth of the mysteries is clearly seen by the natural light of reason, but because of the authority of God Who reveals them, for He can neither deceive nor be deceived." The Vatican Council says, "in addition to the internal assistance of His Holy Spirit, it has pleased God to give us certain external proofs of His revelation, viz. certain Divine facts, especially miracles and prophecies, for since these latter clearly manifest God's omnipotence and infinite knowledge, they afford most certain proofs of His revelation and are suited to the capacity of all." Hence Thomas Aquinas writes: "A man would not believe unless he saw the things he had to believe, either by the evidence of miracles or of something similar" (II-II:1:4, ad 1). Thomas is here speaking of the motives of credibility, the causes which give rise to belief.
In the Catholic Church justification is granted by God from baptism, the sacrament of faith. Joseph Cardinal Tobin said, "...religion is a lifestyle. It means that what I believe influences the way that I live."
Lumen fidei (English: The Light of Faith) is the first encyclical of Pope Francis, issued on 29 June 2013.
Faith (pistis) in Eastern Christianity is an activity of the nous or spirit. Faith being characteristic of the noesis or noetic experience of the spirit. Faith here being defined as intuitive truth meaning as a gift from God, faith is one of God's uncreated energies (Grace too is another of God's uncreated energies and gifts). The God in Trinity is uncreated or incomprehensible in nature, being or essence. Therefore, in Eastern Christianity, God's essence or incomprehisibility is distinguished from his uncreated energies. This is clarified in the Essence-Energies distinction of Gregory Palamas. Faith here beyond simply a belief in something. Faith here as an activity or operation of God working in and through mankind. Faith being a critical aspect to the relationship between man and the God, this relationship or process is called Theosis. Faith as an operation in contemplating of an object for understanding. Mankind's analysis of an objects properties: enables us to form concepts. But this analysis can in no case exhaust the content of the object of perception. There will always remain an "irrational residue" which escapes analysis and which can not be expressed in concepts: it is this unknowable depth of things, that which constitutes their true, indefinable essence that also reflects the origin of things in God.
As God in Trinity, as the anomalies of God's essence or being. In Eastern Christianity it is by faith or intuitive truth that this component of an objects existence is grasp. Though God through his energies draws us to him, his essence remains inaccessible. The operation of faith being the means of free will by which mankind faces the future or unknown, these noetic operations contained in the concept of insight or noesis. XIV. SAVING FAITH.
C.S. Lewis described his experience of faith in his book Mere Christianity by distinguishing between two usages of the word. He describes the first as follows: "Faith seems to be used by Christians in two senses or on two levels ... In the first sense it means simply Belief." Several paragraphs later he continues with "Faith, in the sense in which I am here using the word, is the art of holding on to things your reason has once accepted, in spite of your changing moods."
Protestants differ on the exact relationship between faith and knowledge, although all agree that knowledge is normally involved. Roughly, the split is between paedobaptists and baptists, with paedobaptists asserting that faith means placing one's trust in Jesus Christ according to the measure of understanding granted, and baptists asserting faith means placing one's trust in Jesus Christ with a certain minimal core of understanding being necessary.
Assent to the truth is of the essence of faith, and the ultimate ground on which our assent to any revealed truth rests is the veracity of God. Historical faith is the apprehension of and assent to certain statements which are regarded as mere facts of history. Temporary faith is that state of mind which is awakened in men (e.g., Felix) by the exhibition of the truth and by the influence of religious sympathy, or by what is sometimes styled the common operation of the Holy Spirit. Saving faith is so called because it has eternal life inseparably connected with it, and is a special operation of the Holy Spirit
Paul writes in Ephesians 2:8-9: "For by grace you have been saved through faith, and this is not your own doing; it is the gift of God—not the result of works, so that no one may boast." From this, some Protestants believe that faith itself is given as a gift of God (e.g. the Westminster Confession of Faith), although this interpretation is disputed by others who believe the Greek gender alignment indicates that the "gift" referred to is salvation rather than faith.
Justification is conferred in Baptism, the sacrament of faith.