The ceiling's artwork depicts scenes, such as the last judgment, a large majestic image of Christ as well as the rewards of the saved and the damned. The mosaic shows the plight of sinners in hell suffering punishments like being burned and being eaten by one particularly famous multi-headed monster.
Humanity has always based its beliefs, at some level, on life after death or the lack thereof. Even atheists model a good part of their belief system on the fact that they do not believe in life after death. Reincarnation, Christian resurrection, the Rapture — the list could go on.
So, does a belief in heaven or hell give you a better quality of life? I would argue that it does.
When those we love die
Recently, someone close to me passed away. I had never been through such an experience, and going through it has changed me forever. As humans, we try our best to control everything we can. But death is something we have very little say in.
I have always believed in an afterlife; but after experiencing this death of a loved one, I feel closer to that reality than ever. It simply does not make sense to me that we would feel such love and attachment to others in this life for it not to mean something after death. Knowing this — knowing there is more — changes everything for me.
To be sure is to have peace
Having a surety of life after death has given me such peace and happiness. To believe that I will see my late loved ones again and that they currently exist in spirit brings such happiness, stability and comfort to my life. As I have grown older, it has also helped me in overcoming fear of death.
To know that the part of life I have the least control over, my death, is controlled by a loving God in whom I believe, brings me peace and lessens my anxiety.
The "renters" principle
There is a reason renters put down a deposit. Not having ownership in something, or finding a situation only temporary, naturally creates a situation of apathy. If you don't plan on keeping the house, you probably care less about the amount of holes you put in the wall or spills you make on the carpet. So too with life — if you believe there is more, if you believe there is consequence or progress beyond death, it changes the way you act. Those who believe in an afterlife generally believe that they must act a certain way to be found in a favorable position in their next life.
At the end of the day, my actions are driven by my belief in an afterlife and my goals to attain it.
I believe this is a vastly common condition and naturally will make a person want to and try to be better. With such goals, actions in life become more examined and purposeful, and relationships seem more eternal and of more consequence.