“The ultimate thing we can say about marriage is that it exists for God’s glory. That is, it exists to display God. Now we see how: Marriage is patterned after Christ’s covenant relationship to his redeemed people, the church. And therefore, the highest meaning and the most ultimate purpose of marriage is to put the covenant relationship of Christ and his church on display. (25).” – John Piper
If said so before, but I will say it again: Marriage cannot be “patterned after Christ’s covenant relationship to his redeemed people.” Look at that second little word: “after.” To be “after” something, the other thing needs to be “before.”
When was the first marriage? In the Garden of Eden, with Adam and Eve. When did Christ’s covenant relationship with his redeemed people, the church, start to exist? Only in the New Testament. Okay, you could reason that God’s covenant with Abraham made Abraham’s descendants – some of them – a type of church. But whether the church started with Abraham or with the Christians, marriage was not patterned after it. Marriage existed before.
God did not say marriage exist as a picture of Christ and the church. And reading that into Ephesians 5 does not make sense.