To say "There is no God" would be a massively giant leap of faith.
Using the Scientific Method, we Observe a gloriously complex creation that begs the question, "Where did it all come from, and how?" The Hypothesis is that somewhere in the cosmos exists a Creator--the one we call God (or if one prefers, the Hypothesis could be that there is no Creator--that the cosmos formed by chance).
Now, the Experiment: To look behind every asteroid in the cosmos to find this Creator. As a matter of scientific integrity, you cannot reject or accept the Hypothesis until you have completed the Experiment. And therein lies the problem. It is an Experiment that cannot be completed.
Until the scientist/observer has looked behind every asteroid in the cosmos, as a matter of intellectual integrity no one can prove scientifically, "God does or does not exist."
There may be psychological reasons why someone wants or does not want God to exist, but those reasons cannot be verified with science. To believe or not to believe in God boils down to faith.
So which makes more sense? As Pascal would say, if you choose belief and are right your gain is immeasurable. But if you choose disbelief and are wrong your loss is equally immeasurable.
Until we reach every man…