My proof of the existence of God isn't based on a philosophical point of view or theological arguments. It's not even so much proof, given that one can't prove things you need to take on faith. The whole point is to take those things on faith.
I believe in God because of Spring. Spring is when God gets to show off. Pansies, tulips, and pussy willows. Pussy willows! I can't believe pussy willows just "got here" by some cosmic accident. It's not just the complexity of nature that screams intelligent design. Many people think that the complicated relationships of plants, animals, and even science are an example of evidence that God exists. Perhaps they are right. The fact that one particular plant in Zimbabwe cures some obscure disease or one specific insect contributes to the agriculture of a whole region is indeed miraculous. But I think the opposite is also evidence for the existence of God. As far as we know, the only job of the pussy willow is to be pretty. No real purpose, just pure, extravagant, gratuitous pleasure. And lilacs. As far as I know, the only reason that lilacs exist is to make me exceedingly happy.
Only God could make up stuff like this.