He openly supports and funds elitist ideologies like neoreaction that propose that all human life is not of equal moral value and that some are "just better" than others and more or less that might makes right, which is very contrary to Christian teaching.
Those are two that come to mind instantly. There's many more.
He's pretty clearly a political reactionary who believes in religion as a tool to organize a society. That's a secular belief. Belief in religion as a political tool does not require belief in God. (And on the flip side it's entirely possible to believe in God but not to like or trust religion, which is a secular human institution.)