The reason we are less threatened by an adult invoking God as a reason than Santa is that virtually all of us learn at some point that Santa is our parents or other caretaker. We figure it out or find the presents in the closet or sneek a peek and catch them in the act.
But as we mature, we learn that the more we learn, the more there is to learn, and we will NEVER know all the answers to Life, the Universe, the Human Question, and Everything. We don't even know all of the questions. We do know that some things are out of our control no matter our wealth, power, or social systems, so how do we come to understand them. Everybody experiences this. Some chalk it up to fate, some to God, some to other people.
Spoken like a true agnostic. I concur.