Our rejection of the Imago Dei (Image of God, God’s thumbprint of His nature on our being) is fundamentally a rejection of Him, and we’re worshipping creatures by nature, and therefore must and will worship something.

Because we’re made in His image, nothing less than His full presence and joy will satisfy us and give us ultimate meaning and joy ourselves, which is why the rejection and rebellion of Him as God forces us to other loves, idolatry. The root of all sin is supplanting God for lesser things, idols, which is why the first three commandments deal directly with God himself, and only then gets at the horizontal commands dealing with others.

As Luther put it: “the First Commandment is to shine and impart its splendor to all the others.” We’re made in the image of God and therefore our rejection of Him is a rejection of that image in ourselves, Imago Dei, and from there all other sin and idolatry flows of necessity.