What was Brigham Young's motive to push the Adam-God doctrine?

When our father Adam came into the garden of Eden, he came into it with a celestial body, and brought Eve, one of his wives, with him. He helped to make and organize this world. He is MICHAEL, the Archangel, the ANCIENT OF DAYS! about whom holy men have written and spoken—He is our FATHER and our GOD, and the only God with whom WE have to do. Every man upon the earth, professing Christians or non-professing, must hear it, and will know it sooner or later.