Moses reminds the nation Israel here in Deuteronomy, just before they entered the promised land, of the 10 Commandments they received from God when they stood before Mount Sinai. The first of those commandments was that He, the only true God and the God who saved them out of slavery in Egypt, must be the only God they worship.
And we pray:
You, Lord, are our God and our Savior. You brought us up out of slavery to sin in the world. You alone must be first in our hearts. We cannot serve You and money. We cannot serve You and worldly pleasures. We cannot make another ‘god’ stand beside you and be true worshippers of You. Help us to dedicate ourselves fully to You, LORD, that we be not double-minded or double-hearted, Amen.