He can't do that in America. It's either bigamy, adultery, or desertion, depending how he plays it to get the other wife. You can threaten either jail or taking all the marital assets. You have the law on your side to force him to divorce you first, over the issue of your Christianity. That makes him exit the marriage. Then Raulteetoe's Scripture clearly applies.
Of course, you should first try to pray and love him out of what he is doing. That is in that chapter as well.