In my view, Deism is a religion. Indeed, all of the classical deists referred to it as a religion. They called it a natural religion. However, deism is not a revealed religion.
Thomas Paine called deism a religion. Thus, deism is both a religion and a philosophy. The only true religion is deism.
"The only religion that has not been invented, and that has in it every evidence of divine originality, is pure and simple deism." Thomas Paine