CS Lewis on why you may want to reconsider the importance of your character

Christianity asserts that we are going to go on forever...Now there are a great many things that wouldn’t be worth bothering about if I was only going to live eighty years or so, but I had better bother about if I am going to go on living forever. Perhaps my bad temper or my jealousy are getting worse so gradually that the increase in my lifetime will not be very noticeable but it might be absolute hell in a million years. In fact, if Christianity is true, hell is precisely the correct technical term for it. Hell begins with a grumbling mood, always complaining, always blaming others, but you are still distinct from it. You may even criticize it in yourself and wish you could stop it. But there may come a day when you can no longer. Then there will be no you left to criticize the mood or to even enjoy it, but just the grumble itself going on and on forever like a machine. It is not a question of God ‘sending us’ to hell.  In each of us there is something growing, which will *be* Hell unless it is nipped in the bud.
— CS Lewis, Mere Christianity