Why would holy people (in whatever relevant sense of ‘holy’) reincarnate in Heaven?
Heaven, according to Christianity, is not a disembodied state for ‘spirits’. Rather, it is a future society consisting of fully embodied, physical, robust people who are engaging in highly optimal relationships with other people.
The idea is that holy people will reincarnate (‘resurrect’) into this society.
Assuming reincarnation is plausible (and it may not be, see here – but this is the idea in Christianity), a question is: why would certain people reincarnate in this future society, as opposed to others (i.e., why would some people ‘go to Heaven’ and not others)?
One possible answer is somewhat obvious – people who are ‘holy’ are people who would choose to be in this kind of society.
(This leads to the idea that people who are currently incarnated in some sense may have chosen to do so, for whatever reasons – perhaps.)
So, if people indeed are reincarnated at some future point into this kind of society, it might be because they choose to do so, while others don’t. I.e., Heaven isn’t a reward by God while Hell is a punishment, but rather they are the results of a choice (a kind of ’spiritual physics’), which is set up by our actions here and now. Also see here .