Incenjucar
Legend
I don't recall Invokers having dead gods as part of their core story. They were more directly linked to their deities, almost a more "pure" priest class than the more martial cleric.
That said, yeah, magic comes from many sources.
Divine magic can be channeled from deities or it can come from faith itself and the power of the outer planes - even in the absence of deities
Arcane magic is the background fabric of reality
Ki is the essence of self
Psionics is the mind
Many creatures and classes have magical powers which are not spellcasting, and many are basically entirely magical entities, like elementals.
They're all magic in the broadest sense, but there's no reason they all have to work the same way.
That said, yeah, magic comes from many sources.
Divine magic can be channeled from deities or it can come from faith itself and the power of the outer planes - even in the absence of deities
Arcane magic is the background fabric of reality
Ki is the essence of self
Psionics is the mind
Many creatures and classes have magical powers which are not spellcasting, and many are basically entirely magical entities, like elementals.
They're all magic in the broadest sense, but there's no reason they all have to work the same way.