The more you think about it, if there were an afterlife that is eternal there's no finite crime that could warrant any infinite punishment. Who cares if you get to have your finite life before your infinite life last 15 or 90 years, or how brutal and horrific the transition. Clubbing a person to death, no more or less warrants any party to any infinite reward or punishment, than any other action.
If you really weigh such things you realize that the very prospect offered means that this life is largely pointless and minutia compared to the infinite. Such claims are often is offered by the religious to say that it's super important what we do here because it governs our path in the next infinite life. But, really that makes no sense. It's dictating an illogical system which demands that this life is infinitely important while finitely experienced. There is no good reason to do this. The only reason to suggest a system like this is because the proposition that there is some infinite reward or punishment somewhere is false. If there actually were an infinite punishment or reward the impact of some brief 80-90 years would be 0. As such, any reasonable system would accept this and never dictate the infinite by way of the finite. Whereas if the proposition is false, and this is the only life. Then attempting to give it more value by giving it infinite weight would be a reasonable if poorly executed thing to attempt. Moreso if you tied the rewards and punishments to generally moral comeuppance within this life.
Upon the prospect of eternity, life would be meaningless and as such the sins committed within it would be equally meaningless. If we grant the prospect of heaven and/or hell we must conclude that all people go to the same place regardless of any petty finite crimes or sins. For if everybody went to heaven except for Adolph Hitler who burns in hell, then after a few thousand, million, or billion years all of those people who had a brief nothing of a pre-eternal-life shortened by his actions must agree of the unjust nature of an eternal punishment. Such a system, where Hitler was sentenced to hell, would be hugely unjust and would require the intervention of any slightly compassionate humans.
The only crime in such a universe, would be a crime that causes an infinite punishment. The failure to save a soul, the killing of an unsaved person who might have eventually be saved, or anything that would alter the fate of any soul to hell rather than heaven. But, then this too would collapse. Because this would never happen if this never happened. The Nash Equilibrium of such a system is that everybody should go to heaven, anyway. Because only such a crime as to damn a soul would perhaps warrant such a punishment, and the only way to do that is with an infinite chain of damnation that could never have begun. And in such a case, the only real criminal would be God. -- Where theologically one attempts to place an infinite finger on the scale of importance of life, they only succeed in making the entire system a farce. And the infinite the only thing worthy of measure. If there were such infinite rewards and punishments the only coherent system is a uniform system. But, if there were no such set of rewards and punishments, then making the claim that such a system exists would be logical, reasonable, and likely. For what better to attempt to keep people in line than a stick and carrot. And what better stick or carrot than an infinite stick and infinite carrot. But, if we have infinite carrots laying around, whatever we're trying to achieve is meaningless because some fraction of that infinite would outweigh any finite goals we might have. Heaven and hell make the most sense when they are false propositions. For as a real system, they render the earth largely a pointless pitstop that serves no function and engenders no rewards and punishments regardless of anybody's actions. As a fake system, they make sense to try to solidify religious power and bring people in line with whatever religious or moral behavior you want.
The problem here is that such a system is rife for abuse, it's rife for failure and for primitive notions of morality. Morality gets better all the time, secular ethics which focus on what the best way to live should be and how we can get the best results given an acceptable range of behavior has long outstripped the moral notions within various holy books. The Bible describes what kinds of slaves you should have and how they should be treated, how best to buy women from their fathers, how to sell your children, how to commit genocide, take sex slaves, and when it's acceptable to rape them. The Koran is a small nudge from justifying flying planes into buildings. The Bible easily justifies walking around with signs informing people of God's Hate for various things. The idea of heaven and hell doesn't work as truth, and as a lie to compel adherence it gives a loaded gun to pointless nonsense. While I admit that in a system where there is no form of government outside of the hollow threats of religious comeuppance, it might be preferable to a completely failed state. It's not however the best system or even a coherent system in the end. The likelihood that the system described by beliefs of heaven and hell actually exists, is low because the system places considerable emphasis on our Earthly life, while paradoxically rendering it meaningless. Whereas the likelihood that the system should be presented as true when it's really false, is exactly what we should expect from goat-herding nomads grasping at straws to try and macgyver a system that function as a government without any real government authority. When all you have is hollow threats, go big, or go home.
If heaven and hell are real, the universe is a bizarre paradoxical place that doesn't make sense and is perversely unfair.
If heaven and hell are fake, the universe is exactly what it appears to be. People try to control other people and use threats to do it. And when cooperation is generally useful, such threats can be used cohesively and effectively.
As is often the case, religion makes sense, but only if the things it says aren't true. Because generally there are not only answers to the questions posed, but there are good underlying reasons for the claims. And those claims ultimately make no sense unless those claims are also false.