We do agree that God does exist. We only differ in our belief of what substance constitutes that God and what demands / expectations that God has placed on our existence.Fair enough I guess???
There is stuff that cannot be backed up with tangible evidence, such as the existence of God. I have gotten personal proof of God's existence, which is why I never left the Christian faith despite going through a period of intense doubt and questioning long ago. But that proof I received wouldn't be enough to convince others that God exists.