I kinda think they are. I mean you can have a Philosophy and not believe in a divine creator. But, a philosophy guides the way you interact with society. And I think it would be terrible if we had no GUiDE. And if you are really honest - even atheist adhere to the Default religion/philosophy of the West.
Good philosophy should not and can not follow religion. Because like its child, science, which was once known as Natural Philosophy, it is about the attempt to find truth. Where religion is about the expression of given truth. Moreover, in practice, good philosophy always defers to science and logic, which is not required of religion.
If you think you don’t, your lying. You follow a a calendar that’s biblical. You wear clothes when it’s a heat wave (which in pure non-biblical terms is insane). You take ONE SPOUSE when every natural cell in your body says you are not monogamous (especially males). Don’t lie. Be truthful. The Biblical god tells you to fight nature.