Absolutely correct and well evidenced in the 20th Century by Stalins Soviet Union, Mao's Communist China, Hitlers NAZI Germany and Pol Pots communist Khmer Rouge.
The 50 million or so murdered by these secularists? No big deal in a world where objective ethics rules the roost. After all who's to say their ethos was wrong? Objectively speaking of course.
Hitler credited God for his actions.