New Defender's Study Bible Notes
8:13 believed also. Simon’s “belief” was evidently only a belief in the reality of the signs and wonders performed by Philip (note Christ’s rebuke of this kind of belief in John 4:48; also compare John 2:23-25). These wonders were greater than Simon was able to do with his sorceries (Greek mageia, from which we get our word “magic”), and he was envious. In the early Christian literature, he was called Simon Magus, and was said to be a prominent enemy of the true faith.