This is the point:
"There were no mass murders carried out by these men or by any other person in the name and for atheism."
The implication religionists insist on is that bad things happen due to atheism. However, as pointed out above, these events weren't driven by disbelief in god(s), nor were they due to any lack of religion.

I understand the evidence that Hitler had no belief in god(s) (as well as the evidence of his RCatholicism) but that isn't what drove Hitler. He was obviously motivated by his National Socialist ideology which he thought must clash militarily with Red Communism. He was also driven by discredited racial theories. Here are some of his own words: ...
Hitler told Stein how he had been overcome when he saw the Lance on display in the museum in Vienna. He explained: “I slowly became aware of a mighty presence around it. I sensed a great destiny awaited me and I knew beyond contradiction that the blood in my veins would one day become the Folk Spirit of my people”. Unquote. Source:
https://forum.axishistory.com/viewtopic.php?t=8860&start=15
Does he sound like a rational atheist to anyone?!

The difference between Hitler and Stalin was that Hitler found he could use religion to his advantage sometimes. The Bolsheviks faced an Orthodox Church aligned firmly with the Tsar and establishment. That is why it had to go. It confronted the Communist ideology. German religious groups did little effectively to oppose Hitler and many stood behind the war effort. His only interest was in not alienating religionists from National Socialism or his person.

Hitler, Stalin and Mao were driven by ideology and events and not by their religion or lack of any. Organised religion was either an aid to them or their enemy according to where it assisted or impeded their ideological and political aims.

@ Abhi_Lamsar .....

Check out the Tai-Ping Rebellion ....

"The Taiping Rebellion (1851–1864), usually known in Chinese after the name of the Taiping Heavenly Kingdom (t 太平天國, s 太平天国, Tàipíng Tiānguó) proclaimed by the rebels, was a rebellion in southern China inspired by a Hakka named Hong Xiuquan, who had claimed that he was the brother of Jesus Christ. Most sources put the total deaths at about 20 million, although some claim tolls as high as 50 million"

https://en.wikipedia.org/wiki/Taiping_Rebellion

Hitler wasn't an atheist, and it's hard to take posts seriously when they start with such an obvious falsehood. The term gruesome murderers is a bit vague as well. Genocide and ethnic cleansing is ubiquitously encouraged by the deity depicted in the bible, and it also makes claims that the deity depicted committed acts of genocide itself, including of course a global genocide using a flood.

Humans can be barbaric and commit atrocities, most often when states bestow individuals with too much power, and the rights of individuals are not protected. This is a fact independent of whether the humans in question delude themselves that a deity exists. As I said Hitler was a catholic feeding off centuries of christian antisemitism, and Germany was overwhelmingly christian, the SS only recruited christians into their ranks in Germany at the start of the war, and they ran the death camps.

I have no problem accepting that humans are capable of startling acts of cruelty, both those who believe in a deity, and those who don't. Far more problematic would be how you rationalise a claim that a deity is perfectly merciful when it is depicted as committing acts of barbaric cruelty including torturing a baby to death because it was conceived out of wedlock, and acts of genocide and ethnic cleansing.

1. Hitler was a Christian - Christians attempt to distance themselves from Hitler in the same way they distance themselves from Mormons or JWs. Just because Hitler was not your brand of Christian does not mean the Nazi movement was not Christian. Hitler followed the teachings of Martin Luther.

Martin Luther:
"First, to set fire to their synagogues or schools … This is to be done in honor of our Lord and of Christendom, so that God might see that we are Christians …"
"Second, I advise that their houses also be razed and destroyed."
"Third, I advise that all their prayer books and Talmudic writings, in which such idolatry, lies, cursing, and blasphemy are taught, be taken from them."
"Fourth, I advise that their rabbis be forbidden to teach henceforth on pain of loss of life and limb …"
"Fifth, I advise that safe-conduct on the highways be abolished completely for the Jews. For they have no business in the countryside …"
"Sixth, I advise that usury be prohibited to them, and that all cash and treasure of silver and gold be taken from them …"
"Seventh, I recommend putting a flail, an ax, a hoe, a spade, a distaff, or a spindle into the hands of young, strong Jews and Jewesses and letting them earn their bread in the sweat of their brow … But if we are afraid that they might harm us or our wives, children, servants, cattle, etc., … then let us emulate the common sense of other nations such as France, Spain, Bohemia, etc., … then eject them forever from the country …"

Hitler:
And then proceeded to outline seven steps “good” Christians were to do:

1) Burn all their synagogues;

2) Destroy their homes and businesses;

3) Burn their prayer and holy books;

4) Forbid the Rabbis to teach;

5) Forbid Jews to travel, combine them in special areas;

6) Take all their money, property and valuables; and

7) Make them slave labor.

Isn’t it strange that Hitler did all the above to the Jews? Where did he get the idea? He even went further and reinstated laws that were once initiated by the Church, such as:

1) Jews could not hold public office;

2) Jewish doctors could not be patronized by non-Jews;

3) Jews had to live in special areas, called Ghettos;

4) Jews had to wear a special badge on their clothing with the name JUDE in it.

Finally, simply read Mein Kampf and Hitler's 25 steps of the National Socialist Program (Nazi Party Platform) POINT 24 CLEARLY STATED - FOR ALL THE WORLD TO READ......

We demand freedom of religion for all religious denominations within the state so long as they do not endanger its existence or oppose the moral senses of the Germanic race. The Party as such advocates the standpoint of a positive Christianity without binding itself confessionally to any one denomination. It combats the Jewish-materialistic spirit within and around us and is convinced that a lasting recovery of our nation can only succeed from within on the framework: The common good before the individual good. (Gemeinnutz geht vor Eigennutz).[10] Has also been translated as "The good of the state before the good of the individual".

Mao was a religion unto himself. Communism was the God of the state. You worshiped it or you died. Mao's communism was no different than the Christianity of the Dark ages or the Witch Trials. You believed and were a member of the Church or you were put to death. Mao's communism was religion gone amok.