This is a cause-and-effect universe. There's a note on your door, someone wrote it. The door swings open, something caused it to swing open. Everything springing into being is the effect. If there was absolutely nothing BEFORE everything springs into being, there is no cause to produce the effect. There had to have been a cause, but according to atheists, there was NOTHING before everything sprang into being. Hmm. There had to have been an eternal object, something that is not an effect but a cause, something that isn't created.
That's why I believe in God.