The Problem of Infinite Punishment for Finite Sins

I’ve always struggled with the idea of infinite punishment for finite sins. If someone commits a wrongdoing in their brief life, how does it justify eternal suffering? It doesn’t seem proportional or just for something that is limited in nature, especially when many sins are based on belief or minor violations.

If hell exists and the only way to avoid it is by believing in God, isn’t that more coercion than free will? If God is merciful, wouldn’t there be a way for redemption or forgiveness even after death? The concept of eternal punishment feels more like a human invention than a divine principle.

Does anyone have thoughts on this or any responses from theistic arguments that help make sense of it?