Luther said –

So we always have many precious and comforting promises and assurances of God, of which the entire Psalter and all the gospels, yes, the whole Scripture, are full. These are not to be despised in any way but are to be prized most highly, such as Ps. 55:23 “Cast thy burden upon the Lord, and He shall sustain thee. He shall never suffer the righteous to be moved.” Ps.27 “Wait on the Lord. Be of good courage, and He shall strengthen thine heart. Wait, I say, on the Lord.” Also Christ Himself says, John 16 , “But be of good cheer; I have overcome the world.” It indeed is not false, this I know for sure, that Christ, the Son of God, has overcome the world. Why, then, do we fear the world as if it were a victorious conqueror? A person really ought to fetch such a passage on his knees from Rome or Jerusalem; however, because we have so many such [passages], we despise them. But that is not good.