Brother Albert R.
Jesus loved us and said we should Love our enemies
My response to the title of your post is, we may be responsible for some ones physical death but not their spiritual death. People are responsible for the truth they have, even those who died before Jesus came to earth. To be able to blame someone else for not warning you would be like blaming others for your own faults. God knows the beginning from the end, He will send angels to minister to those who are going to inherit eternal life even though they might not realize they are angels.Where does the blame fall if we as Christians didn't share the gospel with someone? Can it be our fault someone doesn't accept Christ, or does the moral impetus fall solely on that person and his or her decision?
I hope that this helps,
God bless,
Brother Albert