I dont believe we all just die and never come back?

Reincarnation is not at all possible. No one lives after death in any form and there is no afterlife. There are spirits but they are separate elements. A human being during his/her lifetime is living with many spirits which have joined one by one since birth. They are knowledge, skills, feelings, emotions, interests and everything. These spirits are your consciousnesses and memories. Even thoughts are not your own. For example, when you want to take a decision on a subject, one after another the spirits think and you just listen, choose or reject the ideas which they transmit to your mind through your brain in the form of thoughts. Brain is just a media to connect the spirits to your mind. A mind is just a computer's mind. A mind is you. After the destruction of a computer completely you will not get its mind. The same is the case with the human beings.  A human being doesn't have a spiritual body. Soul is nothing but an energy needed for the functionality of a body. It is not a spirit or anything else. A body's functionality is based on the auto mechanism.  After death all spirits which accompanied a person quit and go to different places searching new bodies. No one lives after death in any form. All human beings are just robots made of flesh and bones and toys of the spirits for their games.

There is no hell or heaven for human beings. They are only for spirits. I guess that the heaven is just the sky and hell is the prison for spirits. Good spirits are free to go anywhere in the sky but bad spirits are put in prison for certain years. I guess that certain evil spirits are destroyed completely. Spirits' lifetime is limited. If what they (spirits) have said is true then they live approximately for 400 to 500 years. This is close to the Indian Hindu's belief that a human being has seven births. That means Hindus believe in reincarnation but I don't.

REINCARNATION

I was believing in reincarnation for many years but after I have started to hear the spirits’ voices inside my head in the year 1983 (age 32) and after observing their conversations for years and after knowing the fundamental things about computers, I have come to a conclusion that all human beings are just robots made of flesh and bones and toys of the spirits for their games and there is no reincarnation.

To form a reincarnation all spirits which lived with a body must possess another person together. Then only he/she can feel the same person who died. But this is not happening because the spirits never stay together to haunt or possess another. They go searching new bodies. Rarely there might have been certain cases but I think they have changed after some time. I mean, they (humans) didn't able to remember anything after certain age. Spirits during their life time live with many bodies (one after another). Their memories sometimes affect the person. This is natural. This is not enough to believe that there is rebirth. No one returns after death. All human beings’ lives end with their own bodies.

There is always a common fate which is always applicable to all creatures including human beings. That is, human beings are like other creatures except that they have an additional sense (sixth sense). This sense had changed only the living conditions of the human beings but not the fate. The fate is almost same to all creatures including human beings.

You are right; we don't die and that's the end.

God created us for two reasons: 1) because He loves us, and 2) to be with Him forever in Heaven. 

"Now this is eternal life: that they may know you, the only true God, and Jesus Christ, whom you have sent."

   --- John 17:3

remember Jesus Christ resurrected his friend Lazarus here on earth. if Lazarus was in heaven, why would Jesus bring him back to earth, just to die again and go back to heaven? because Lazarus was not in heaven, in was in the grave waiting for the resurrection here on earth. 

There is to be a resurrection of the righteous and the unrighteous (Acts 24:15). The majority of people will live on earth in perfect conditions (Psalms 37:29; Revelation 21:3, 4; Isaiah 33:24).

You sound biased.........................

While I don't believe your argument is logically valid, your final conclusion is of course correct, since God has clearly stated that it is so. There is indeed an afterlife. But it doesn't happen on Earth.

Jesus is the only portal into heaven... it starts here and now. Go to him for entry and you will indeed become immortal.

 Thats your problem then entirely

Don't make assumptions and you'll be more happy. You may be surprised as to how far from here things may differ in the future.

What's the purpose of death if we just come back?

And no, we do not live for long, our lives a microscopically tiny compared to universe.

Just because you feel the need for a reason does not mean or prove an afterlife.