Deuteronomy, written by Moses, contains the key truth of God's law and His live. It was written between 1405 and 1400 B.C., shortly before the death of Moses. The key verse in Deuteronomy is found in 10:12 and says, "And now, Israel, what doth the LORD thy God require of thee, but to fear the LORD thy God, to walk in all his ways, and to love him, and to serve the LORD thy God with all thy heart and with all thy soul..."