There's a great book you should read "Think" by Simon Blackburn He has a chapter he dedicates to analyzing the various arguments for the existence of God. The Cosmological Argument contradicts itself, and the other have various other flaws. I don't have the time to type it all up, but just in case you actually care. To address your particular argument, you claim that everything has a cause, so there must be an [i]original[/i] cause. The flaw here is that by conceding that God is the origin and has no causation for [i]his[/i] existence, you can no longer make the initial argument regarding causation therefore the universe would [i]not[/i] require an original cause.