There was a time when God the Father was alone before he was a father and he looked to the future and saw that his creation would sin and a God would have to be incarcerated emptying himself of all divine powers so he could go to earth and die to save mankind but God had a problem because there was only one God so who would hold the universe together while this other God was incarnated and once he died to save mankind. Who would resurrect him and bring him back to life? So this is why God decided to have a son and after his birth from the Father his Son created us all.