Faith in Christianity is often discussed in terms of believingGod's promises, trusting in his faithfulness, and relying on God's character and faithfulness to act. Some denominations believe in theNew Covenant and in the doctrine ofsalvation byfaith alone (sola fide). According to mostChristian traditions and denominations, Christian faith requires a belief in theresurrection of Jesus, and theAgony in the Garden which Jesus states is the plan ofGod the Father.[1][2][3]
Since theProtestant Reformation of the 16th century, the meaning of the termfaith has been an object of majortheological disagreement inWestern Christianity. The differences have been largely overcome in theJoint Declaration on the Doctrine of Justification (1999). The precise understanding of the term "faith" differs among thevarious 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.
Some of the definitions of faith in the history ofChristian theology have followed the biblical formulation inHebrews 11:1: "Now faith is the assurance of things hoped for, the conviction of things not seen".[4]
Christian faith builds onOld Testament faith because the promises of the Old Testament are accepted as being fulfilled in the ministry, suffering, death, and resurrection of Jesus Christ.[5]
The word "faith", translated from the Greekπίστις (pi'stis), was primarily used in theNew 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 ofpi'stis ispisteuo, 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' usingpi'stis-group words. Thepi'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 offirmness 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 bypi'stis. Thepi'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 ofpi'stis-group words in the New Testament is a matter of recent controversy, particularly over the meaning ofpi'stis when it is directed towards Jesus.[6]
Now faith (pi'stis) is the assurance of things hoped for, theconviction of things not seen.
— Hebrews 11:1[7]
This passage concerning the function of faith in relation to thecovenant of God is often used as a definition of faith.Υποστασις (hy-po'sta-sis), translated "assurance" here, commonly appears in ancientpapyrus business documents, conveying the idea that acovenant is an exchange of assurances which guarantees the future transfer ofpossessions described in thecontract. In view of this,James Hope Moulton andGeorge Milligan suggest the rendering: "Faith is thetitle deed of things hoped for".[8]
In recent decades, scholars have researched whatpi'stis meant in the social context of the New Testament writers. Several scholars who have studied the usage ofpi'stis in both early Greek manuscripts and the New Testament have concluded that 'faithfulness' is the most satisfactory English translation in many instances.[9][10] 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.[11]

TheCatholic Church considers that faith is twofold.
Assent to divine revelation on the basis of God's truthfulness is termed "divine faith"; this is distinguished from "human faith," which is the simple assent to the propositions of other human beings.[13]
According toThomas Aquinas, faith is "the act of theintellect 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 giftsupernaturally bestowed upon the understanding, so also thisdivine grace moving the will is, as its name implies, an equally supernatural and an absolutely gratuitous gift.[14]
"We believe", says theVatican Council (III, iii), "thatrevelation 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. certainDivine 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." HenceThomas 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).
In the Catholic Church,justification is granted by God from baptism, the sacrament of faith.[15]Cardinal Joseph Tobin said, "religion is a lifestyle. It means that what I believe influences the way that I live."[16]
Faith (pistis) inEastern Christianity is an activity of thenous or spirit. Faith being characteristic of thenoesis ornoetic 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).[17] The God in Trinity is uncreated or incomprehensible in nature, being or essence.[18] Therefore, in Eastern Christianity, God's essence or incomprehisibility is distinguished from his uncreated energies. This is clarified in theEssence-Energies distinction ofGregory Palamas.[19]
As God in Trinity, as the anomalies of God's essence or being.[clarification needed] In Eastern Christianity it is by faith or intuitive truth that this component of an object's existence is grasped.[20]
In theProtestant 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 theProtestant Reformers. One of their confessional statements explains: "the principle acts of saving faith are accepting, receiving, and resting uponChrist alone forjustification,sanctification, andeternal life."[21] The Reformers contrasted faith with human efforts to dogood works as a means of justification.[22] This understanding ofsaving 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 ofatonement accomplished through his death on the cross.
According toLutherans, saving faith is the knowledge of,[23] acceptance of,[24] and trust[25] in the promise of the Gospel.[26]
C.S. Lewis described his experience of faith in his bookMere 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."[27] 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."[27]
Paul writes inEphesians 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. theWestminster Confession of Faith[28]), although this interpretation is disputed by others who believe theGreekgender alignment indicates that the "gift" referred to issalvation rather than faith.[29]
James O. Mason said that there need to be 4 steps to increase ones faith.[30]
Alma the Younger describes faith as a seed inAlma 32 in theBook of Mormon. This is the most comprehensive explanation of faith in theStandard works of theLDS Church.[35]
John's gospel is intended to conduct people to saving faith in Christ.
Justification is conferred in Baptism, the sacrament of faith.