“Then sang Moses and the children of Israel this song unto the LORD, and spake, saying, I will sing unto the LORD, for he hath triumphed gloriously: the horse and his rider hath he thrown into the sea… Thou shalt bring them in, and plant them in the mountain of thine inheritance, in the place, O LORD, which thou hast made for thee to dwell in, in the Sanctuary, O Lord, which thy hands have established.” Exodus 15:1,17

Most of those men who sang this song unto the Lord never made it out of the wilderness because of their hard hearts. Though they sang that the Lord would plant them all in the mountain of the Lord, a place He has made for them to dwell, they never believed it. It is one thing to sing songs to the Lord, it is another to believe what you are singing.