How about a Jewish answer?
I am no longer a Christian (though I was a Methodist minister 30 years ago), so I can't help you there; but I'll try to give you the Jewish version.
First, Jews aren't 100% sure that there is a Heaven to begin with. Most think so, but few will tell you that they think it's guaranteed. It isn't mentioned in the Torah, and was apparently absent in the early years of our religion.
Second, even those Jews who do believe in an afterlife don't think about it much. It just isn't very important. The focus of our religion is on THIS life. Whatever happens afterward, if anything, is God's business, and we tend to leave it up to Him.
Third, we don't believe that anyone knows, or can know, how God will judge anyone, not even himself--no, not even infants.
(Speaking for myself, for all I know, one must at least reach the "age of reason" and exercise some sort of autonomy before one rates a life after this one. Who knows? I certainly don't. Jews don't even ask such questions. I probably couldn't even think in those terms had I not been born a Christian.)
Fourth, to Jews, life is sacred. Period. Since this life is all we for sure have, it is evil of the purest ray serene to throw it away, either our own or anyone else's, in favor of a very uncertain assurance of a life afterward of which we know nothing. Which brings us to:
Fifth, even those Jews who do believe in an afterlife do not claim to have any idea what it might be like. There are some indications in Scripture that it's a rather dull and dreary place where nothing much happens. The party is on the first floor; why leave it to go sit in the basement with the lights out? The elevator to the penthouse might not work--or it might turn out to be a one-story house.
The short answer, I suppose, would be to say that it's a pretty stupid question.
At first I thought it was asked tongue-in-cheek, and I suppose in a sense it was; but I've only been hanging around here a short time, and I've already noticed that many of the questions that atheists ask the religious are thought to be clever traps that the stupid, benighted believers will find impossible to answer. In some cases, that might even be true; there are stupid, benighted believers in the world. There are others, though--and some of them are even Christians--who are aware that such questions merely betray a shallow, stereotypical understanding of what religion is and how it affects one's life and influences one's decisions.
As I said, I can no longer speak for Christians; but I suspect that a typical answer might be, "That would be a HORRIBLE thing to do!"
And that answer is a good deal more intelligent and meaningful, not to mention "humanistic" and "rational", than the question was.