A certain current trend in auto-brainwashing is to assert that "All Wars Are Started by Religions!"

But consider the actual record of killing by the messianic-atheistic, secular humanist regimes of the 20th century, as recorded at the University of Hawaii's Freedom, Democide, War, Power Kills website.

Mao 70,000,000
Stalin 60,000,000
Hitler 20,000,000
Total 150,000,000

The 20th century's Big 3 death toll far overshadows
the worst European war of religion (regrettable as that smaller number is):

Thirty Years War 5,750,000
Compared to three
20th century dictators
3.8%

Mao killed 70 million, Stalin killed 60 million, Hitler killed 20 million, the 30 Years War, brought to you by "the people who start all wars", killed: 5.75 million, 3.8% of the Big Three 20th century total.

But all this is infinitesimal in comparison with the incalculable death toll of the innocent unborn—if they're not Persons, neither are you—at the hands of Marie Stopes, Margaret Sanger, NARAL, NAF, the Rockefeller Population Foundation, the Ford Foundation and UNFPA–easily half a billion, with no end in sight.