In the old testament there are examples of men with multiple wives. God did not expressly forbid multiple wives; but, he did desire that men have only one wife.(Dt17:17 He must not take many wives, or his heart will be led astray...) This verse is for the king but you can apply it to regular men too. All of the patriarchs had more than one wife or at least a wife and a concubine or slave girl who bore them children. Abraham, Isaac, Jacob (Israel) and his son's. In the new testament we are told to have only one wife.( Corinthians 7:1-2 1 Now for the matters you wrote about: It is good for a man not to marry. 2 But since there is so much immorality, each man should have his own wife, and each woman her own husband.)