Why is ISIS killing everyone in villages that they capture except the girls and Women?

There are several reasons for this. First, they can sell the women and girls to the highest bidder. Second, it is a way to expand their ISIS population base. As soon as a girl or woman can bear a child they will. If they can get this child to 18 to 20 years of age it is a new fighter for ISIS.

This might happen unless the woman or girl finds a way to kill her raper or forced husband (same thing).

If you look at the Old Testament of the Bible this was how things were done a lot in the Old Testament before the time of Christ. Whole nations were killed except the girls and women then then the conquering soldiers took many of the girls and women as wives and bred with them. This goes on in country after country in the Old Testament which is likely why ISIS is doing this now again.

In Old testament times Rape and forced marriage was a way of life as whole nations of men and boys were often killed by other nations.

I'm not saying this was a good thing I'm just saying that is likely where ISIS got this idea. So, likely you are going to see wherever they go this go on. So, if you have girls or women in areas where ISIS likely is going to take over I would recommend you get them away from there to Europe or the U.S. or anywhere this won't happen to them too.