If you are decidedly religious, you should skip this section. If you decide to proceed anyway, don't be offended !
"But you can't prove there _isn't_ a god." The burden of proof is on the claimant. Extraordinary claims require extraordinary proof. There is no need to postulate an omnipotent intelligence governing the universe. "What caused the universe?" The universe is that which is, it is us who come into existence and cease to exist. It is also our responsibility to understand the universe, and not chalk up every mystery to some omnipotent force, or worst yet, to go searching for mysteries so as to reinforce superstition.
Death is, by definition, the end of life. "Life after death" is a contradiction. When a tree dies, it's dead. When a dog dies, it's dead. When a monkey dies, it's dead. When a man dies, he's dead. End of story. Get over it, accept it or whatever, just don't dwell on it.
Religion and superstition have been responsible for more harm through the centuries than any other socio-political force. About the only beneficial aspect of religion is a Machiavelian usefulness for regulating the irrational members of society.
Religion has many hooks. Any animal wants to survive. Tell a man that there is the slightest possibility of infinite life and if he has even the slightest belief, you've got him. If he is "agnostic", he will assign a 50% probability to what you say. 50% of infinity is infinity. Even for a skeptic, 10^-6 times infinity is still infinity. Perhaps this helps to explain why it is such a struggle to rid oneself of superstition...
The universe appears to be efficient. Energy is not "wasted" as it moves toward a maximum entropy state. Life is a part of the efficient use of energy. Intelligence is one way for life to minimize energy requirements, it is more efficient to think than to use brute force. Perhaps, and this is very unlikely, but it may be that the knowledge gained in a lifetime is not wasted, it is somehow re-used. This would make sense as far as efficiency is concerned, but one or more of the premises of this argument is likely to be in error.