Marriage, New Vs. Old

Q. For many years now I have been wondering why it was acceptable for men in the Old Testament to have multiple wives and concubines ( and I am assuming they had sexual relations) while in the Church today you are either living in adultery or not saved if you have divorced and remarried .  The guilt can be quite overwhelming at times. Thank you for any help you can give.
A. In Ephesians 5:22-32 we learn that  the Lord views marriage as a model of His relationship with the Church.  Paul taught that the man should love his wife just as the Lord loves the Church, and to give himself completely up for her, treating her as if she’s absolutely perfect and can do no wrong. In return the wife should submit to her husband just as the Church submits to the Lord.  Since the Lord swore that He would never leave the Church, if a man leaves his wife he’s violating that model.   Marital infidelity on her part is the only justifiable cause for divorce, because it’s as if the Church had chosen another God to worship.

That said, divorce is no different from any other sin.  It’s man who has made it seem unforgivable, not God.  If you’re divorced you can ask the Lord to forgive you and He will. His mercies are new every morning, and He doesn’t hold a grudge.  He knew every sin of your life before He agreed to save you and took them all to the cross.