To live by faith is, by faith in Christ, to possess the whole Word of God as our own in all states and conditions, resting quietly upon His gracious and faithful promise and yielding ourselves unto His good pleasure in sincere, universal, and constant obedience. Or to live by faith is to feed upon the several promises of God made in His Word and to apply them to our own selves, according to our needs, and so to uphold, comfort, and encourage ourselves against all temptations and unto every good duty.

— Isaac Ambrose (1604-1664)
“The Practice of Sanctification” in Works