Once upon a time I believed in Santa Claus. I was told by people who I trusted that Santa was real and that he did wonderful things. I was told that he watched me all the time to make sure I was doing right. And, if I didn't do right, I would get nothing but switches for Christmas! I was a pretty good kid and I did get some presents on Christmas, so I loved Santa and thought he was a really great guy.
Then one day, some of my friends started telling me that Santa wasn't real. They said that the whole story was ridiculous because no one could do what Santa was said to do. After I thought about it, this made me question Santa's very existence! But, I did not want the story of Santa to be untrue. I had invested something like 4 years of my life believing in Santa, so how could I turn away from him now? How could I let go of the Santa fantasy and all of the wonderment of Santa and live a life reduced to plain reality? It was a very difficult time for me.
And so it is with religion. Not just the Christian religion, but all religions. The stories have been passed down over the years and changed by various groups and used to control the masses. Many wars have been waged in the name of religion and some of the most religious people in history have done unspeakable things to others in the name of religion.
It took me a while to get to where I am, but I have evolved from Christian to Agnostic to Atheist. I am only Atheist because I think that saying you are Agnostic is kind of a cop out. As an Atheist, I do not know there is no God, but I certainly do not believe that there is. I also do not believe that if there is a God that he is in the same form or plays the same role as what we have been led to believe through the Christian religion.
Think about this. There are an estimated 100 billion galaxies in the universe. Our Milky Way galaxy is average in size and it is estimated to contain up to 400 billion stars including our sun. Our sun has 8 planets (sorry Pluto) orbiting it. Humans are but one of 8.7 million species living on just one of those planets. We are literally a gnat on a gnat's ass in the grand scheme of things. Now, given all of this, do you really think that there is a supreme entity who listens to the every thought of 7 billion people and is just waiting to lift the believers into heaven to join him in everlasting bliss once they die?
Sorry, but it is far more likely that Santa Claus is real.