There is a 100% certainty that God exists, while simultaneously, there is a 100% certainty that God doesn’t exist.
How so? It all comes down to the origins of the universe, or the multiverse. Mathematically, our universe can come in an infinite number of designs. It just so happened that this design allowed the development of carbon as well as just the right amount of gravity to ensure the development of stable planets and stars.
This universe may have developed and imploded an infinite number of times before, and this time, it came out of the mixing pot looking like this. Or, this may be its first birth, with the infinite number of other designs occurring in other universes.
We don’t know.
What we do know is that the design of this universe, from our perspective as humans, is pretty freaky, because it has to be exactly so to have allowed us to exist at all.
And this is why the existence of God is a 100% certainty, while at the same time a 100% certainty that there is no God.
For mathematically, the design of this universe is a mathematical inevitability, albeit there may have been many other flops before we got to this point. But equally, it is hard to deny the possibility that the mathematical inevitability is in itself a random event.
So both answers are possible.
But who can deny sitting at the ocean’s edge, and at that instant when day turns to dusk, wondering at the majesty of it all, and whether, we really are alone and whether this life is all a matter of chance.
I for one would be very sad to believe that our existence is nothing more than a random draw of the cards. But I don’t know.