In Matt 19 and Mark 10 Jesus is challenged about divorce and He quotes the Genesis creation accounts. Of course when God says let 'us' make mankind in 'our' image, male and female, the us and our includes Jesus (In the beginning was the Word..)
So the image of God is a man and a woman, and the reason Jesus says is so that a man shall be united with his wife and the two shall become one flesh.
That is why Jesus speaks against divorce because it breaks the image of God. It would also be with for example domestic abuse, that would be abuse against the image of God. And of course a man and a man coupling isnt even the image of God or the purpose of God.
But many Christians cite the sermon on the mount as wonderful teaching of Jesus, such as blessed are the poor, but the sermon is from the time He went up on the mount to the time He came down, ie Matt 5-7 and in that time He teaches do not divorce.
Very difficult for those who come to Christ and have divorced because society or even some churches see no problem with it, because the union has already been broken. Thankfully Jesus is about the forgiveness for sin and the renewing of one's mind in Him.
Potentially disastrous news for church leadership that condones it though.
