How can you possibly believe one part of the Bible, and throw out another part?

I came across an answer to a question earlier that said "not all Christians believe in Hell, but all believe in God", or some nonsense like that. I don't get how that is supposed to work. If you don't believe in Hell, then why would you need to believe in God? His whole reason in wanting us to believe in Him and accept Him is to prevent us from GOING to Hell. So how does that make sense? I mean if you're an atheist and you don't believe, that's one thing. But taking some of the Bible and just tossing the rest of it out? that's truly messed up. I mean Jesus himself said He would rather us be "hot" or "cold" than be "lukewarm." There is no happy medium, really. Why would you do that? ~Call me whatever you want, I AM a conservative Christian, Bible thumper, whatever you call it.