What am I?

You are Agnostic.

I am Atheist. There is no god, and there simply cannot be one. It is far from close-minded. It's simply being realistic. I believe that beings of higher power exist, but they had nothing to do with our conception, nor the creation of the universe.

Close minded was the wrong term.

I honestly would like to say that I do not believe in any sort of thing supernatural. Unfortunately I use higher powers to explain what I can't understand.

The biggest thing that I can't understand is how did matter come into existence in the first place, since it cannot be created nor destroyed. Are there any valid theories on this?

I've come to the conclusion that I don't believe in anything supernatural, but my mind tricks me into thinking of the supernatural to fill in the gaps.