Side note, this particular part of the mentioned Black Mirror serious still haunts me. And the guys sin was not that terrible...talk about cold heart/snap decisions.
I would forget about such things as technology and study of death, and read the Bible in full ---New Testament, and not just taking verses at random; and see that one needs to be saved ("born again" by the Holy Spirit) to enter Heaven. All else in the Bible is just about obeying and honoring God, and being a Godly testimony until He calls His dear saints to Himself. Religious ideas and reasoning therein is a ploy of Satan.