What you need to learn on earth is “relevant to existing in heaven” only in the sense of being taken into the companionship of Holy GOD.
What’s that? For reasons mankind will probably never find consensus on, we are the creations of a holy and loving GOD – yet for having free will and for needing to be evvvvver so slightly inconsiderate of others just to stay on par, we are not holy and we are not pure.
Yet GOD is holy, and fair. HE sent the second part of the trinity, the WORD, to confine himself (toss away his own divine power) into human form as Jesus to take our place, expunge all of our punishments [bad karma if you will] – and all that is necessary on our end is to acknowledge our debt. That results in us bringing “broken and contrite hearts” to GOD in prayer to ask for forgiveness. It’s in the Lord’s Prayer.
GOD grants mercy, washing, forgiveness, purification – at death the Christian soul (meaning broken and contrite) emerges as a pure and holy being in a perfect body (whatever that is) eternally accepted into the fulness of GOD’s love.
What’s relevant to heaven? I have no clue. I just know the actual price of admission.