It still needs actual power.No, it doesn't. At least not in 3e or 4e, and 2e apparently with the Priest book. 5e went back to deities only, but that seems like an oversight
The power for your Heal spell comes from somewhere.
You need to have link to an item power or create your own.
It's next level. Again a normal cleric is powered by a god which is able to choose to give them power on their own whims.That's a cleric man. It's zealot level faith that gets the attention of the god
A cleric of a philosophy has to tap into a philosophy that has power.
And if you're The only cleric if a philosophy that means you have to power that philosophy on your own.
Even in D&D regular people don't just believe themselves into divine power.
I mean dragons are genetically predisposed to think they are the hottest @#$& in the world to the point that they don't even trust their own children because their children come from them and therefore must be almost as awesome as they are. And dragons can't just cast heel harm and raise dead and flame strike via their own hubris.
You have to be a special person. A special level of fanatical zealous crazy. Like literally lawful stupid and extremely hardheaded for your philosophy.