So, to the simple question, what should he do [with his mistresses] now that he is saved?
Send the women away. Pay for the upkeep of the children but by all means separate him from those women. They are not his wives and they should not be made to be. That’s what happened in the example in the book of Ezra mentioned in a prior part of this series.
If he had married them by his culture’s accepted custom for marriage, then they should stay but should anyone of them decide to leave him because of his new found faith, they should not be held against their will. But that is for married couples, not co-habiting couples. I am not an expert on the legal systems of the world but I think the legal provisions for a marriage are different from co-habitants and possibly de-facto partners no matter how long they’ve been together or how many children they have.
Part 4 is still to come.
See part 2: http://wp.me/p6rlMY-1h