God is warning Israel to be wary and to not become entangled with the inhabitants of the land when the time comes to possess the land which God promised to Abraham. He does not want the Israelites lured away by the gods of the land and thereby diminish their worship of the one and true living God.
Likewise saints, we are not to become entangled with the ways of the world. Our citizenship is in heaven and our hearts belong to Jesus. We need to walk cautiously (Ephesians 5:15), making sure we do not become lured away into activities, sinful or otherwise, that diminish our worship and devotion to the Lord. Father, guard our hearts and minds, and by your Spirit, give us the desire and strength to keep our focus solely on You.