Clearly the one that is going to kill your child is evil and, if you are inclined to believe it, is going to hell and sinning against God.

When you kill that person, you have joined them in also sinning against God — irrespective of what your reason was.

I'm not taking a side here but just pointing out that Quakers have a very clear directive that goes, more or less, thou shalt not kill.

(It's perhaps a bigger surprise that countless other Christian religions have all kinds of addendums that I guess allow for that one.)