I was an agnostic for most of my life, but have settled into a much more refined understanding of the universe.
To me, God is what creates and holds the universe together. When you meditate or pray, you can connect to this force and center or settle your emotions. The bliss you feel on a sunny day, say you're walking on a pier and there's a nice breeze. That there is God. The various imperfections that have crafted each and every individual biological organism on this planet, they are necessary. The constant change and fluctuations of energy.
I feel that's what God is on a physical level. But on a moral or emotional level, I believe inspiration should be drawn from all manner of existing religions. Personally I closely identify with the Christian faith. This doesn't mean I believe God created the world in 7 days, Old Testament etc. etc... But, I do believe in the teachings of Jesus, and I believe he was a righteous man who taught righteous ideals and saved people. I also believe in the teachings of Buddha. I hold Taoism very close, as this was my first entry into spiritual belief, learning about Taoism is what I needed to get a fuller grasp on how I felt about God.