Earlier quoted context omitted.
If the reward cited above in Matthew 6 isn't absolution then it is still effectively similar if it's a pleasant afterlife.
It isn’t. A primary tenet of Christianity is to identify with Christ, mainly through suffering. Much the way a workout can be rewarding in and of itself (e.g. the runner’s high), the suffering of sacrifice can be its own reward if given in the correct mindset. What makes this possible for the Christian believer is the faith/knowledge that one’s sins have already _been_ absolved, so Heaven has already effectively been…
I have yet to meet a Christian believer IRL who has actual faith that their sins have already been absolved so heaven has already effectively been attained
Maybe that's more common in other corners of the world? I haven't met many people who actually act as if they know they'll be saved as opposed to hoping they'll be saved