I personally believe that there exists an entity who created the universe. But I have absolutely no issue with Atheists. My belief is personal, held for personal reasons. I cannot prove the existence of this higher consciousness that I believe in, so why would I expect anyone else to share my belief?
Here's what stresses me: according to the ever-reliable Wikipedia, of the ~7 billion people on the planet in 2010, about 80% of them were affiliated with one of 16 major religions. This means that 4 out of every 5 people I meet will believe that they are the lucky winners of the religion lottery, having chosen correctly among all religions, past, present, and future, and are now privy to the secrets of the universe.
The scale of this delusion is mind-boggling. Let's hypothesize there is a true religion. Then it follows the others would be false. How many others are there? Depending on how granular you want to be the answer is between 1 (everybody is right) and the world's population plus one (everybody has a different wrong idea, and the right idea) Since having more people believe one idea does not affect whether it is correct or not, that means the odds that the average person has chosen the CORRECT religion are pretty low.
I believe this is the first thing obscured by the religious mind: that numbers do not matter, only what they believe. Every injustice perpetrated by religion seems to spring forth from this immense conceit. It seem that, ironically, most people instinctively shield themselves from statistics while seeking the Truth.
I agree, that's a problem with religion. Who can say which one is right? That used to bother me when I was religious. I knew that the Jews and Muslims and Hindus all believed in their religion, just as I believed in Christianity. With my eternal soul in the balance, how could I be sure which was correct? Why wouldn't God just tell us how he wanted us to be? That's why it was so liberating when I dropped all that crap.
If there is a God, he clearly doesn't care what people do. I mean, he created the Universe. Think of the immense power and ability of such a being! Why would he get bent out of shape over what a bunch of creatures on one little planet in one little galaxy do? He operates on such a level that we cannot begin to comprehend. That's why I don't believe in sin. I don't think God needs to be worshiped. That's a primitive belief, from when the Earth was all there was. Now we know there is so much more. God doesn't care if we kill each other. How could it possibly make a difference to him? I think he probably feels bad for us, because we still haven't figured out how to get along with one another, rather than trying to dominate one another. But then, I'm probably just projecting.
So, of course every religion is wrong. I'm probably wrong too. But religions have to be Right! Each one is the only way to salvation! And that's the problem. They all think they know the Truth and use that belief to justify all kinds of terrible things. It would be better if they had the humility to understand that a belief in God is not about right and wrong. As you point out, how can one say what is right about a being that created the Universe? And as I pointed out, we can't know for sure either way. If such a being exists, we cannot possibly know its mind. A belief in God is just about what helps you in your life. Don't kid yourself, we all have our delusions. As long as they're not used to dominate others, I let people have them.