Salam
I believe God is the best of all possible creators and would not create a world like this, except it has infinite meaning and purpose. The reason without infinite reward or punishment, the whole thing is a joke and meaningless. If it's just a lesson as some Kahens (sorcerers who channel devils) say, it's meaningless. If incarnations till you get it right, it's meaningless, life, it's a guarantee of success and overlooks and doesn't reward one's life nor punishes the evil ones for their evil choice.
I believe infinite doubling and doubling reward and similarly believe if one dies in the direction of evil, the punishment is infinite amplifying. The gates of hell are just different type of punishment and the speed of amplification is different, but as Quran says 'for everyone is doubling of the punishment if you only knew".
The reward and best reward in paradise is love of God and his light, it's looking at the favors of God in paradise which the center of it is Ahlulbayt (a). Ahlulbayt (a) are the center of reality of paradise and also, they are related to Angelic reality, and Angels reality is linked to the reality of how "the fire" and "painful" punishment occurs. Because inwardly, evil, is hell, and our actions will come to life.
I believe right now hell and paradise is hidden, when dying, it's reality is more hidden to disbelievers although they gain a different type of sense, they don't realize the punishment they are in, and only the day of judgment, will they recognize hell and will it be brought to view.
Believers after dying, because they gain spiritual organs, taste of paradise, but even they won't know it's full appreciation till the day of judgment. It's then the rivers of light, the Ahlulbayt (a) are seen for the wonders they are.
God through linking himself to us and through pressure of death and time, has created life of limited time but with infinite result and meaning. We get it wrong, we pay the price forever, we get it right, and we get rewarded. This is what good and evil is. It's not a joke, and it's not something to risk. Far above it will God not pressure creation to be good nor pressure them to absolve from being evil. Death is a reality none can escape.