"You shall not bow down to them or serve them, for I the LORD your God am a jealous God, visiting the iniquity of the fathers on the children to the third and the fourth generation of those who hate me."
God is not petty and insecure like most jealous people are. His love is not so easily wounded by our playing the harlot under every tree on every hilltop. Even though it is God's jealousy which causes the destruction of sin (through the "visiting of iniquity"), it is this same jealously which keeps us from dying. God's jealousy leads us to salvation.
God simply refuses to let us depend on anything else other than Himself and in so doing refuses to let us die for putting our trust in anything but Christ is a sure death. God's jealousy is a refusal to let those whom he has called bow down to or serve other things because God's holiness is in direct opposition to that which harms us and causes us to not thrive. Just as a gardener destroys weeds or a doctor eradicates disease, so to does this jealous God remove from us our sins that we might live consecrated and holy as He is holy. Then and only then can we live life in righteous fellowship with God.
Praise be to our jealous God who overcomes our sins that we might live! Praise be to our Creator, Savior, and Perfecter who makes us holy and blameless before him!