In the Old Testament faith is more described than defined. It has been described as:
a. the “fear of God” (Gen. 20:11; Ps. 111:10; Eccl. 12:13; Mal. 4:2) Psa 11:10 NIV The fear of The LORD is the beginning of wisdom; all who follow His precepts have good understanding. To Him belongs eternal praise.
b. Trust (2 Chron. 20:20; Ps. 4:5, Isa. 26:4) Psa 4:5 NIV Offer right sacrifices and trust in the LORD.
c. obedience (Ex. 19:5; 1 Sam. 15:22, Jer. 7:23) Exo 19:5‑6 NIV Now if you obey me fully and keep My Covenant, then out of all nations you will be My treasured possession. Although the whole earth is Mine, {6} you will be for Me a kingdom of priests and a holy nation. These are the words you are to speak to the Israelites.
Despite the lack of an English equivalent for the word faith in the Old Testament that does not mean that faith is not important for the Old Testament. Habakkuk 2:4 “but the righteous will live by his faith”‑‑ was properly taken by Paul as the center of Old Testament religion. (Rom 1:17; Gal 3:11; Heb 10:37-38)
New Testament
In the New Testament “faith” is used in a number of ways, primarily with the meaning “trust” or “confidence” towards God.
a. The Gospels emphasized faith as one of the central themes of the sermons of Jesus.
Mark 1:15 introduces and summarizes the Gospel with Jesus’ charge to his hearers to “repent ye and believe The Gospel.” (The word commonly translated “believe” in this verse, the verb form of “faith”, has no English equivalent. The call is repeated as “Have faith in God,” using the noun form, in Mark 11:22.) In this way Jesus challenged His hearers to place their trust in God. Jesus often said after healing someone, “thy faith hath made thee whole.” (Matt. 9:22; Mark 5:34; Luke 7:50; 8:48). Trusting in God makes one whole.
b. Outside the Gospels, faith is discussed as being necessary for the basic Christian doctrines such as salvation, sanctification, justification and purification. As in the Gospels, faith is the nature of our relationship to God through the work of Christ Jesus. It is to acknowledge and accept the gift of righteousness in Christ, that which cannot be earned or achieved in our own strength.
c. Faith is among the fruit of the Holy Spirit (Gal. 5:22) – something God creates in a person. Gal 5:22-23 (KJV) But the fruit of The Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, 23 Meekness, temperance: against such there is no law.
d. Faith is also described as a gift of The Holy Spirit (1 Cor. 12:8‑9). Special gifts of faith refer to the ability to do great acts for God, what Jesus called moving mountains (Matt. 17:20; 1 Cor. 13:2). 1 Cor 12:8‑9 NIV To one there is given through the Spirit the message of wisdom, to another the message of knowledge by means of the same Spirit, {9} to another faith by the same Spirit, to another gifts of healing by that One Spirit,
e. Faith is used to designate Christianity itself, or a union of that which we believe (our belief system or our creed).
(Acts 6:7; Eph. 4:5; Col. 1:23; 1 Tim. 1:19; Jude 3). Acts 6:7 NIV So the Word of God spread. The number of disciples in Jerusalem increased rapidly, and a large number of priests became obedient to ‘the faith.’ Here it is clear that belief is essential to the personal relationship with God we are calling “faith.” Further note Hebrews 11:6 “But without faith it is impossible to please Him: for him that cometh to God must believe that He is…. “In this verse also, the word translated “believe” is the Greek verb form of “faith.” Right relationship with God requires us to “believe” that God is, that God has revealed Himself in Christ, and to accept the fact that God has accepted us.
f. Faith is also the living out of our Christianity;
It is Christianity in action. “We walk by faith, not by sight” (2 Cor. 5:7). “Walking” represents the lifestyle and actions of the believer. Paul wrote that faith – the trust and confidence one puts in God – directs our actions in life. Faith changes the standards and priorities of life. In describing a soldier’s armor, Paul demonstrates the importance of faith, comparing it with a shield against sin and evil in our lives (Eph. 6:16; 1 Thess. 5:8).
g. If Christianity itself may be called “the faith,” then the verb form of faith can also designate Christians. This form is often translated “believers” (it occurs most often in the plural) or “those who believe” (Acts 4:32; Rom. 1:16), “those who have faith” or “those who share their faith”. (Acts 4:32 NIV) “All the believers were one in heart and mind. No one claimed that any of his possessions was his own, but they shared everything they had.”
h. Faith as THE Way to Salvation
1. The scriptural concept of faith is a personal relationship with God that determines the priorities of one’s life.
Faith is:
(a) A relationship of trust and dependence that is based on love.
(b) Received by trusting in salvation through Jesus.
(c) The basic Christian experience, the decision for Christ Jesus.
(d) The acceptance of Christ’s Lordship (i.e., His God‑given, absolute authority).
(e) Repentance: it denotes a turn in lifestyle, and one’s removal from sin, and it is one’s removal from all other religious allegiances. (1 Th 1:9 NIV) for they themselves report what kind of reception you gave us. They tell how you turned to God from idols to serve the Living and True God,
(1.) As a break from the past, faith is the beginning of relation to God in which one continues to grow and develop.
Faith is what we believe, it is Christianity itself. Primarily it is our relationship with God through the work Jesus accomplished in His death and resurrection.