Premise 1 is inaccurate; generally, modern Christians believe children that die before a certain, undefined age go to heaven out of the mercy of God. A more mystic belief is that they go to a non-Purgatory, temporary realm that's neither heaven nor hell. Premise 4 is flawed because loving others more than yourself does not mean sacrificing your own salvation. You'll notice that Jesus never sinned to save anyone. In addition, Premise 3 is incorrect because Christian doctrine is generally of justification by faith, meaning that a mother that kills her children may very well go to heaven. However, following this reasoning indicates the person never really understood their faith. So the only correct premise is #2, and the logically appropriate action a Christian should take would be to help guide their children spiritually. At face-value this question sounds somewhat reasonable, but it really just doesn't hold up to even the slightest scrutiny. I would argue that most Christians do not, in fact, believe 1-3 are true.