A.T. Robertson Commentary 1 John 4:5

"They are of the world: therefore speak they [as] of the world, and the world heareth them." — 1 John 4:5 (ASV)

Of the world (εκ του κοσμου). As Jesus is not and as the disciples are not (John 17:14ff.).

As of the world (εκ του κοσμου). No "as" (ως), but that is the idea, for their talk proceeds from the world and wins a ready hearing. The false prophets and the world are in perfect unison.