This was touched upon in a game called Indika released this year......there's a story there how a guy ended the suffering of his young child who was in constant pain, and was told by a priest during confession time "well you see by killing your son you condemned your soul to eternity in hell, but your child is now definitely in heaven, so actually you did a good thing by sacrificing yourself!". And so the guy went and killed the rest of his family, having come to a logical conclusion that he can't get any more condemned to hell than he already is, but if he guarantees that his entire family goes into heaven then surely that's an absolutely amazing thing to do. I don't know if this was based on a true story or not, but the logic totally applies.