Genesis 36:2, 3 Esau took his wives of the daughters of Canaan; Adah the daughter of Elon the Hittite, and Aholibamah the daughter of Anah the daughter of Zibeon the Hivite; and Bashemath Ishmael’s daughter, sister of Nabajoth.
Esau responded to God’s Grace and Promise by going the way of the unbelieving world around him. He had ”despised his birthright” and was tricked out of the first blessing from his father. Now he shows his unbelief in God and rejection of the Covenant by ignoring the wishes of his parents by marrying into the ”world,” which is at enmity with God’s Kingdom.
A whole chapter is given to the descendants of Esau, the Edomites, but they become enemies of the people of God, the children of the covenant. In this way the Lord is revealing to us that there are only two kinds of people in the world: believers in God through Jesus Christ and unbelievers, who live in a different world and are enemies of God and His children.
It may not seem like a serious offense to us, but it is a deadly sin to God. It is dangerous and death-dealing for the members of the Kingdom to marry those of the opposing kingdom. And just because it happens all the time does not make it OK. We heed the warning of Paul in 1 Corinthians 6:14-16: ”Do not be unequally yoked with unbelievers…what partnership…what fellowship…what accord…what portion…what agreement…?” Unlike Esau, we are careful what commitments and entanglements we make with the unbelieving world.