One only needs to look at the metaphors of the bible regarding Christ and His bride the Church to understand that the God goven order of things is one man one wife. Further, one just needs to look at the initial creation story to see that God intended one man one wife. He did not create Adam and Eve(s).
Yes. In His discourse on marriage Jesus Christ reminded the Pharisees of God's original intent for marriage. One man and one woman united for life. There is not doubt that many Jews had adopted the practices of their neighbors and no longer held to what God had originally blessed.
But Jesus Christ restores us to a life incorporated with the Trinity. Marriage not only reflects the truth about Christ and His bride the Church. It also is a reflection of the life giving love of the Trinity. It is not just a social constraint but a Holy sacrament and as such an instrument of grace. Polygamy denies this and mocks God's
revealation about marriage.
That is exactly what I was going to say!