The second act of faith.

Herman Witsius has written:

“To this knowledge must be joined assent, which is the second act of faith, whereby a person receives and acknowledges as truth those things which he knows, receiving the testimony of God, and thus setting to his seal, that God is true, John iii. 33. This assent is principally founded on the infallible veracity of God, who testifies of himself and of his Son, 1 John v. 9, 10. On which testimony revealed in scripture, and shedding forth all around the rays of its divinity, the believer relies with no less safety than if he had been actually present at the revelation of these things. For when the soul, enlightened by the Spirit, discerns those divine truths, and in them a certain excellent theoprepy, or beauty worthy of God, and a most wise and inseparable connection of the whole, it cannot but assent to a truth that forces itself upon him with so many arguments, and as securely admit what it thus knows, for certain, as if it had seen it with its own eyes, or handled it with its own hands, or had been taken up into the third heavens, and heard it immediately from God’s own mouth. Whatever the lust of the flesh may murmur, whatever vain sophists may quibble and object, though perhaps the soul may not be able to answer or solve all objections, yet it persists in the acknowledgment of this truth, which it saw too clearly, and heard too certainly, as it were from the mouth of God, ever to suffer itself to be drawn away from it by any sophistical reasonings whatever: “For, I have not followed, says the believing soul, cunningly devised fables, when I believed the power and coming of our Lord Jesus Christ, but in the Spirit was eye witness of his majesty, and heard his voice from heaven,” 2 Pet. i. 16, 18. And thus faith is accompanied with [greek], substance, and [greek], evidence, Heb. xi. 1. and [greek], full persuasion or assurance, Rom. iv. 21. It will not be unprofitable to consider a little the meaning of these words.”

(Witsius, Herman. The Economy of the Covenants Between God and Man, Volume I, Kingsburg, CA: den Dulk Christian Foundation, 1990, p. 377-378)