Deuteronomy 7:14 You will be empowered above all peoples; there will be no infertile male or female among you or your livestock.
Deuteronomy 7:15 Yahveh will remove all sickness from you; he will not place on you all the terrible diseases of Egypt that you know about, but he will inflict them on all who hate you.
Deuteronomy 7:16 You must destroy all the peoples Yahveh your God is delivering over to you and not look on them with pity. Do not worship their gods, because that will be a snare to you.
The Israelites were to be like an invincible army of supermen. They would have more children, be impervious to common diseases, and wipe out everyone who dares to oppose them.
But these supermen would be vulnerable to one Kriptonite. Worshiping other gods would remove their protection. If they failed their God, they would be condemning themselves to destruction.
Lord, burn this fact into our memory so that we stay true to you.