I am a christian for 3 reasons: 1. My family is christian. 2. The universe and solar system is so perfectly ordered that it seems unlikely that we and the universe were randomly created. And the third reason is because i liked the idea of eternal happiness after death. I didnt want to see nothingness after death.
1. Your family being Christian does not therefore make you a Christian for life. My family is Catholic, but I am an atheist.
2. The Universe is perfect? Maybe if you don't take into account the BILLIONS of failed solar systems continually collapsing on themselves this very minute. When it comes to life being on earth, and earth being just right to support life, you are still wrong.
There are trillions upon trillions of planets in our universe. Even if the chances were EXTREMELY low for life being created by planets being correctly positioned in solar systems, its bound to happen not one time, but even thousands of times at least. There is nothing special about us.
3. Just because somethings nice does not make it true. I find that your reason for being a theist is the same reason I am atheist. The idea that I literally only have one life to live does not hurt me, but inspires me. It tells me that I need to do the best I can now, and that I should not wait for greater days. It makes me value life much more.
You also make many assumptions that if you are an atheist you believe the world was created by chance, which is wrong. The same goes for nothingness after death. Atheist's simply claim a skeptical position, saying that they do not know how the world was created or what happens after death.