Q: What is faith in Jesus Christ?
A: Faith in Jesus Christ is a saving grace, whereby we receive and rest upon him alone for salvation, as he is offered to us in the gospel.

Q: What is repentance unto life?
A: Repentance unto life is a saving grace, whereby a sinner, out of a true sense of his sin, and apprehension of the mercy of God in Christ, doth, with grief and hatred of his sin, turn from it unto God, with full purpose of, and endeavour after, new obedience.

(Questions LXXXVI and LXXXVII from the Westminster Shorter Catechism.)