Will humans ever go extinct?

Humans will go extinct. No doubt about it. 99% of all species that ever lived are now extinct. Humans have lived for only 3 or 4 million years. That is a short time. We are a new species. 

If we keep having wars and building nuclear weapons, our extinction will be very soon. 

If we could inhabit a livable planet and moved there just in time we would actually survive. The Earth will be destroyed and unlivable but if we can go to space we could survive.

Yes.  Not long now.

Yes, humans will go extinct and almost certainly as a result of their own actions. It will be great news for all other species.

One day, this planet we inhabit will cease to exist. When it dies - and it will, we will die with it.

Don't worry, though, it won't happen for a few billion years. All planets die, eventually.

Uncle Fester has summed it up very well.

Sure

If we keep worshipping money/capitalism, we may be done before the year 2200

If we make the right choice we may be around for several millennia - but not by the billions

It is inevitable. Whether we die out or change, humans will cease to be.  When you consider what a species is you should not think of the individuals that exist at any one time but the cloud of available genes that are within the species as a whole. That cloud of genes moves forward through time, dropping some attributes and gaining others, hopefully adapting to changing environments. As humans move forward they will, if they exist long enough, cross an undefined line between species. 

There are species that do not change over long periods, ones that are in tune with the environment to such a degree that change is not needed or indeed desired, the Coelacanth for example, but eventually even they will have to change or die. Of course one day our planet will become too hostile to support any life, if we have not left by then even what we have become will perish.

If you take the Bible and many cultures history literally, then yes.

Many cultures history tell us there were worlds before us, like we are the 5th generation of the human species.

Even the Bible says the Gods said "Go forth and REPOPULATE the world".  Since Adam & Eve were the first humans, how is it possible for them to REpopulate the world unless mankind was killed off previously?

"Ever" is a long, long time. However, humans have brains that can come up with technology to sustain life, should they have the foresight to do so, whether it's on this planet or some other.