The Scriptures are clear that what we can know of God is only that which he has revealed to us of himself. There is no way we can find out anything about God except through his revelation. Even then, we must be careful not to speculate beyond what God has said.
The pre-eminent revelation of God is of course through Christ, God in the flesh, come to dwell among us. As Jesus said, He who has seen me has seen the Father. There is nothing more that we need than that.
Sermon: The glory of the unseen God