“Promises, promises!!” we say, mockingly, when we know or suspect that the promise is not going to be kept! But when the Lord makes promises He means them, He means to keep them, and He means His people to trust them as they plan the future. He looks to us to obey His commands; He looks to us to trust His promises. Indeed it is as we trust His promises that we find ourselves able to obey His commands: it’s called “the obedience of faith.” Abraham is the father of those who believe (Rom. 4:11). Genesis 15:3-6 tells how he “simply” believed what God promised: Romans 4:18-22 reveals how totally his faith rested on the word of promise, taking account of everything that stood against it; Hebrews 11:17-19 describes how he held to the promise even when it was challenged by death itself. And he was proved right. Since it is through faith in the Lord’s promises that we are saved (Acts 16:31), then surely, if faith is mighty to solve the great and eternal problem of our sinfulness, alienation, and helplessness, is it not the way to tackle every problem–to look up to our almighty, ever-loving God and say “I trust you”?
— Alec Motyer, Isaiah by the Day, 47.