What is your image of the invisible God when you focus on him in prayer, since we worship an invisible God?
I don't have any image and I think I ought not to. If I want to know what God is like, as a Christian I think of the way the Lord Jesus behaved, how he spoke, what he said, how he acted and what he's done. But as for having a mental image of God, I don't have one and I think we're not meant to try and have an image of him. He goes beyond all our imaginations. We know of him through his word, through what he has done, and supremely through Jesus Christ our Lord. We don't even have a picture of the Lord Jesus, and that I think is deliberate.