This question already has an answer here:
It might sound a bit naive but,
How is it that conservation of energy is never broken, how is it that we know that always and for sure the energy in our universe is constant and we cannot create a destroyed energy.
I mean is there any mathematical and physical mechanism in the real world that has prevented this from happening or is it just that we have not been able to find any case where energy is being created from nothing that we have led to this conclusion?
Similarly for charges to how is it that in the universe all the charge that is created is conserved.