birdie; In the 20th century the total number of deaths brought about by secular acts unmotivated by any religious ideology whatsoever, number around 200,000,000;
World war 1, 37,000,000
Mao Ze-Dong (China, 1958-61 and 1966-69, Tibet 1949-50) 49-78,000,000
Adolf Hitler (Germany, 1939-1945) 12,000,000 (concentration camps and civilians deliberately killed in WWII plus 3 million Russian POWs left to die)
Leopold II of Belgium (Congo, 1886-1908) 8,000,000
Jozef Stalin (USSR, 1932-39) 6,000,000 (the gulags plus the purges plus Ukraine's famine)
Hideki Tojo (Japan, 1941-44) 5,000,000 (civilians in WWII)
Pol Pot (Cambodia, 1975-79) 1,700,000
Kim Il Sung (North Korea, 1948-94) 1.6 million (purges and concentration camps)
Leonid Brezhnev (Afghanistan, 1979-1982) 900,000
Tito (Yugoslavia, 1945-1987) 570,000
Suharto (Communists 1965-66) 500,000
- and there are many, many more. Compared to these figures the amount of deaths brought about purely by religious activities (though regrettable) are by comparison very small indeed.