[Serious Discussion] Religion

[STyL4]

It's retarded either way 

I have a question: Why do christians (if not all, then some) believe in the world end?
Didn't God make some kind of a deal with Noah (involving rainbow) after flooding the world that he would never do such thing (killing 99.9% of the mankind) again, because of seeing that people didn't change?
Or is the world ending some completely different story?

I don't really know much about this stuff, so pardon my newbieness.

// Killing people isn't really the same as sending them to either hell or heaven, but I don't wanna delete my question

im back , in the Bible we're warned that we can't really predict world's end and so on because only God knows when's the real ending and so on and we're also warned about false prophecies, gtg cya.