Never said that it proved that there is a God. However, I am glad you agree with me that atheism leads to immorality.
And I didn't say that either. Atheism doesn't have to lead to immorality. An atheist is simply someone who does not believe in any deities and that allone says nothing about him being a moral or immoral person (unless you consider a lack of belief in a god or especially your god to be immoral).
Sure, a belief in a god can prevent people to kill each other as well as it can lead some to fly planes into buildings depending on what is believed that such a deity wants.
It's similar to being told that you are roasted alive if you push a certain button. Even if that isn't the case it prevents you from actually pushing that button if you believe what you're being told. But why should someone tell you that? Well maybe because that person thinks (or knows) you're not capable of understanding what really happens if you push that button. So as long as you don't push that button it doesn't really matter why you refrain from doing it.