Hear me out on this.
So far, there is no evidence of the Maker, or worship thereof, before Andraste.
And, according to “The Search For The True Prophet” book ingame, there is reasonable evidence to suspect Andraste was a Mage of some sort.
Furthermore, according to Corypheus, one of the Magisters who unleashed the darkspawn and the first blight, the Golden City, home of the Maker (whom andraste was devout to) was Black when the Magisters arrived.
So what we know is that the Maker is//was being who provided Andraste, a potential mage, with enough power to stand up against Tevinter, an incredibly powerful magic-ocracy, and win.According to a firsthand witness, the Maker’s home was black and corrupt for ages before the Magisters.
What I’m getting at here is, perhaps the Maker isn’t a God, but rather a fade-dwelling being capable of providing mages with extraordinary power.
Such as a demon?