In old age we are like a batch of letters that someone has sent. We are no longer in the past, we have arrived.
Grieve not, then, if your sons seem to desert you, but rejoice, rather, seeing the will of God done gladly.
A universe with a God would look quite different from a universe without one. A physics, a biology where there is a God is bound to look different. So the most basic claims of religion are scientific. Religion is a scientific theory.