What is the ultimate concept of God?

God is not limited to personality even to the degree that we who are spirit are limited.

Try to be satisfied with the knowledge that God is present to the remotest part of the Universe, and that God is a God of Love and Justice and Mercy. 

Never doubt this.

The more spiritual you become, the nearer you grow to that blessed spiritual presence, and the more nearly you approach, the more your spirit is filled with love, awe and reverence.

Be content to serve with the love of God in your heart, and sometime your knowledge will be perfected.