So God created man in his own image, in the image of God created he him; male and female created he them.
-Genesis 1:27, KJV
Divorcing a cheater would not hurt as much if she was pure evil.
That is my opinion. I am not saying what she did was anything less than evil. That is pure evil. Such is adultery (see Deuteronomy 22:22).
My point is that even a cheater is made in God’s image. They do not live up to that image by choosing a dark path with their sinful actions.
However, they still bear His image.
This manifests in the good memories we have of our cheater. Those memories highlight the qualities that are arguably still good in them or once were so.
That said, I feel it important to tell you that it is okay to acknowledge those good things and still not want to be married to the cheater.
We do not need to dehumanize our cheater in order to leave him or her for our own well-being.