Divine Power Sources
Druids and adepts channel the power of the Life Stream
Clerics get their power from their belief in the gods, and not directly from the gods, a god can infact use the worshipers as a medium to draw power from the Life Stream to create outsiders. Clerics that follows an ideal draws power directly from the Life Stream, this has proven to be harder than using a god as a focus.
Oracles is granted their power from a god, in almost the same fashion is which the gods create outsiders.
Inquisitors, Paladins, Anti-Paladins, Hell-Knights and Liberators gets their power from the head of their church, who channels it directly from the Life Stream.