Êxodo 20

Êxodo 20:3

Again, he who says "you shall never worship a strange god" forbids us to worship another god, and the strange god is so called in contradistinction to our own God. Who then is our own God? Clearly, the true God. And who is the strange god? Surely, he who is alien from the nature of the true God. If therefore our own God is the true God, and if, as the heretics say, the only-begotten God is not of the nature of the true God, he is a strange God and not our God. — ON THE FAITH