There is no such thing as a "mystical union" with Christ. The scripture knows only of our covenantal union with Christ which began with the shedding of the blood of the covenant. His blood was shed before the foundation of the new order and not before the creation of the earth and of Adam.
Circular. This view assumes that the expression "before the foundation of the world" means "before all eternity." It does not. It means "before the foundation of the new order."
The marriage union is not a "mystical" union. Neither is it "deep mystery." It is a covenantal union that has a beginning. All cultures understand this.
We were married to Adam. Our union with Adam was dissolved when we died to the law. This freed us to be married to another which is Christ.
Or do you not know, brethren (for I speak to those who know the law), that the law has dominion over a man as long as he lives? 2 For the woman who has a husband is bound by the law to her husband as long as he lives. But if the husband dies, she is released from the law of her husband. 3 So then if, while her husband lives, she marries another man, she will be called an adulteress; but if her husband dies, she is free from that law, so that she is no adulteress, though she has married another man. 4 Therefore, my brethren, you also have become dead to the law through the body of Christ, that you may be married to anotherto Him who was raised from the dead, that we should bear fruit to God.
We were first married to and divorced from Adam. Then we were married to Christ. Our divorce and re-marriage occurred before the foundation of the new order and not before the creation of the earth and of Adam.
If a child cannot understand it then it's wrong.