It is popular to have on line debates between believers and atheists.
To my mind - this is like having a debate whether one should slaughter his mother. There are strong reasons not to but it is a debate. That would be horrific. The moment there is a debate it legitimizes both sides. There is no legitimacy to slaughtering one's mother רח"ל. Nobody in their right mind would justify such a debate.
G-d is not subject to debate. There are not two sides. We can debate if WE truly exist but not Him. HE and only He is the true existence [as per the Rambam at the beginning of יסודי התורה].
The Rambam also writes that one may not even entertain thoughts that go against the principles of our faith [הל' ע"ז ב-ג].
It is also important to remember that in the 20th century, Hitler, Stalin and Mao Zedong [the Chinese communist leader who starved about 45 million of his people] caused the deaths and indescribable suffering of tens of millions. The common denominator of these three monster-demons was that they had no G-d.
A favorite quote of mine:
"What Hitler did not believe and what Stalin did not believe and what Mao did not believe and what the SS did not believe and what the Gestapo did not believe and what the NKVD did not believe and what the commissars, functionaries, swaggering executioners, Nazi doctors, Communist Party theoreticians, intellectuals, Brown Shirts, Black Shirts, gauleiters, and a thousand party hacks did not believe was that God was watching what they were doing. And as far as we can tell, very few of those carrying out the horrors of the twentieth century worried overmuch that God was watching what they were doing either. That is, after all, the meaning of a secular society.”
