The author starts by giving a little bit of background on Nimrod (the "Rebel"...like Alinsky's Lucifer) who was "anti-God" (perhaps a Nephilim or offspring of Fallen Angels). He didn't doubt God's existence. He rebelled against God and sided with his forefathers in their allegiance to Satan, Shaytan, Shemyaza, Lucifer (or whatever his name).
Point is...that sect has a god it serves, albeit a god of perversion and evil.
Darwinism and secular humanism are an entirely different sect in not just rebelling against God but declaring that he doesn't even exist. It appears that the secular-humanists are the useful idiots of the Luciferians in a manner similar to how the Marxists in the present world are useful idiots for Islam and Allah.
Like Nimrod, early revolutionaries like Marx did not doubt God’s existence either. This is why Marx and similar thinking revolutionaries chose to call themselves antitheists rather than atheists. They knew that God exists but set their wills against Him and forbidding the asking of questions, required blind submission in all things. In obedience, the ‘new’ Marxist, Soviet, Darwinian, secular humanist man asks no questions and by way of destructive criticism, ridicule, scorn, etc. permits no one else to ask them either.
Whereas Nimrod’s sect served a deity of evil (Satan, Shaytan, Shemyaza, Lucifer) early antitheists did as well. From Marx to Saul Alinsky, they acknowledged Lucifer as the first free-thinker, the one who liberated man from the ‘evil’ God of creation, the god in whose genetic image they are made, the god of evolution, and so on.