Fair warning, I'm going to be talking about religion.
Tell me if you heard this before.
"I believe what I believe and you believe what you believe and that's totally okay. Let's just all respect each other's beliefs and get along in peace and harmony."
Bet you have. This is a very common, very politically correct, thing to say whenever we brush against the possibility that someone else might have different beliefs then us. It sounds very nice and tolerant and respectful and well... I would never say it. I never could.
Please understand, it's not because I don't respect you, or I want to stir up trouble, or think I'm better then you or anything like that. It's just that if I ever said that it would be one gigantic betrayal of not only my beliefs, but you as well. Let me explain.
As you may or may not know, I am a Christian. As a Christian I hold certain beliefs (obviously) I'll try to explain them in the most straightforward way possible.
God was here before the universe began and he decided to create us to be His children and the universe as a place for us to live. So he created the first man and woman (Adam and Eve) and put them in a garden that was to be their home. Now God loved Adam and Eve and He wanted them to love him too. But (this is important) it's impossible for anyone to love anyone if they do not have the choice to hate them as well. If you must love someone because it is physically impossible to do anything else, then it's not real love. So God gave Adam and Eve free will, the option to hate him if they so choose. God gave them a boundary, He said "You can't eat the fruit of this particular tree. If you do you will die."
Adam and Eve chose to eat the fruit of the tree. Yes, Satan tricked and lied to them because he hated them (he hates all of us) but he didn't force them. They chose to do it. They chose to disobey God's clear instructions and rebel. That's what sin is. Doing something God told you not to. Now God of course knew what was going on but He let Adam and Eve do it because He was respecting the free will that He gave them. It did break His heart though.
Now what sin does is separate us from God. This made all parties involved very sad. Adam and Eve didn't want to be separated from God and He didn't want to be separated from them but they had made their choice and they couldn't take it back. This was when God instituted animal sacrifices. Because the payment for sin was death, something had to die. God put together a system where animals could die for people's sins. It was a band-aid at best and wasn't a permanent solution but that was okay, God had a plan.
Fast forward a bit and we come to Jesus. Jesus is God. Jesus is also human. Jesus came to earth and did what none of us could ever do. He lived a perfect life and never sinned once. Because of this when he died he wasn't dying for his sins, he was dying for all of ours. And that was it, done. All the sins anyone had ever or would ever commit were paid for. We weren't separated from God anymore because Jesus took care of it for us.
However, we still have free will. God allows us the choice to either accept or reject Jesus's death. If we accept then we go to heaven when we die and we get to be with Him. If we don't then we go to hell, which is permanent separation from God.
I hope, then, that you understand why the whole "You believe whatever you want to believe and I'll believe whatever I want to believe." saying rubs me the wrong way. If I were to say that to you I would be saying, "You're going to hell and that's okay." I do not hate you that much, or at all.
So please, even if you think I'm an idiot for believing this, try to understand where I'm coming from. We all spend eternity somewhere and I want you to spend it in heaven.
(I tried to explain everything as well as I could but if you have questions about it please feel free to ask and I'll do my best to answer.)