What is faith in Jesus Christ?
Faith in Jesus Christ is a saving grace1, whereby we receive and rest upon him alone for salvation, as he is offered to us in the gospel2.
Scripture proofs
The Westminster Assembly's proof texts (KJV). The bracketed numbers in the answer above mark the clause each set of references supports; expand a row to read the verses.
1 Eph. 2:8-9; cf. Rom. 4:16
Eph. 2:8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
Eph. 2:9 Not of works, lest any man should boast.
Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all,
2 John 20:30-31; Gal. 2:15-16; Phil. 3:3-11
John 20:30 And many other signs truly did Jesus in the presence of his disciples, which are not written in this book:
John 20:31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
Gal. 2:15 We who are Jews by nature, and not sinners of the Gentiles,
Gal. 2:16 Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
Phil. 3:3 For we are the circumcision, which worship God in the spirit, and rejoice in Christ Jesus, and have no confidence in the flesh.
Phil. 3:4 Though I might also have confidence in the flesh. If any other man thinketh that he hath whereof he might trust in the flesh, I more:
Phil. 3:5 Circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, an Hebrew of the Hebrews; as touching the law, a Pharisee;
Phil. 3:6 Concerning zeal, persecuting the church; touching the righteousness which is in the law, blameless.
Phil. 3:7 But what things were gain to me, those I counted loss for Christ.
Phil. 3:8 Yea doubtless, and I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them but dung, that I may win Christ,
Phil. 3:9 And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
Phil. 3:10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
Phil. 3:11 If by any means I might attain unto the resurrection of the dead.
This doctrine across the Standards
Where the Confession and the Westminster Larger Catechism treat the same matter, so the question can be studied alongside its parallel statements.
In the Westminster Confession
XI.2 Faith, thus receiving and resting on Christ and his righteousness, is the alone instrument of justification; yet is …
Faith, thus receiving and resting on Christ and his righteousness, is the alone instrument of justification; yet is it not alone in the person justified, but is ever accompanied with all other saving graces, and is no dead faith, but worketh by love.
→ XI.2 · Of JustificationXIV.1 The grace of faith, whereby the elect are enabled to believe to the saving of their souls, is …
The grace of faith, whereby the elect are enabled to believe to the saving of their souls, is the work of the Spirit of Christ in their hearts, and is ordinarily wrought by the ministry of the Word; by which also, and by the administration of the sacraments and prayer, it is increased and strengthened.
→ XIV.1 · Of Saving FaithXIV.2 By this faith a Christian believeth to be true whatsoever is revealed in the Word, for the authority …
By this faith a Christian believeth to be true whatsoever is revealed in the Word, for the authority of God himself speaking therein; and acteth differently upon that which each particular passage thereof containeth; yielding obedience to the commands, trembling at the threatenings, and embracing the promises of God for this life and that which is to come. But the principal acts of saving faith are accepting, receiving, and resting upon Christ alone for justification, sanctification, and eternal life, by virtue of the covenant of grace.
→ XIV.2 · Of Saving FaithXIV.3 This faith is different in degrees, weak or strong; may be often and many ways assailed and weakened, …
This faith is different in degrees, weak or strong; may be often and many ways assailed and weakened, but gets the victory; growing up in many to the attainment of a full assurance through Christ, who is both the author and finisher of our faith.
→ XIV.3 · Of Saving FaithIn the Westminster Larger Catechism
Q.72 What is justifying faith?
Justifying faith is a saving grace, wrought in the heart of a sinner by the Spirit and word of God, whereby he, being convinced of his sin and misery, and of the disability in himself and all other creatures to recover him out of his lost condition, not only assenteth to the truth of the promise of the gospel, but receiveth and resteth upon Christ and his righteousness, therein held forth, for pardon of sin, and for the accepting and accounting of his person righteous in the sight of God for salvation.
→ Open Q.72Q.73 How doth faith justify a sinner in the sight of God?
Faith justifies a sinner in the sight of God, not because of those other graces which do always accompany it, or of good works that are the fruits of it, nor as if the grace of faith, or any act thereof, were imputed to him for his justification; but only as it is an instrument by which he receiveth and applies Christ and his righteousness.
→ Open Q.73Q.153 What doth God require of us, that we may escape his wrath and curse due to us by reason of the transgression of the law?
That we may escape the wrath and curse of God due to us by reason of the transgression of the law, he requireth of us repentance toward God, and faith toward our Lord Jesus Christ, and the diligent use of the outward means whereby Christ communicates to us the benefits of his mediation.
→ Open Q.153