The grace of faith is the Spirit's fruit - William Huntington

"The grace of faith is the Spirit's fruit: he produces it under his operation, and testifies of, and exhibits to the mind, the object to be believed in. The Spirit persuades the mind of interest in that object, and produces the appropriating act of faith to make the application. Faith, the act of it, and the exercise of it, is wholly depending on, and owing to, the Spirit of God, who is the Spirit of faith. If this wind blow not on the Lord's garden, no spices will ever flow out grateful to him who can eat nothing but his own pleasant fruits. And he that turns the mystery of the gospel into a legal rule, and makes the above faith, in its nature, act, and exercise, the duty of the uncircumcised, he proclaims to the world at once that he never yet, with the heart, believed unto righteousness; for he cannot make confession with his mouth to salvation. The mystery of faith is the law of the Spirit, or the Spirit's law; and it is under his divine operations and influence that evangelical obedience is produced: both service and worship must be performed in the newness of the Spirit, and not in the oldness of the letter." -William Huntington