30. But it is equal irreverence to detract from the dignity of the Father, or the Son, or the Holy Spirit. For he believes not in the Father who does not believe in the Son, nor does he believe in the Son of God who does not believe in the Spirit, nor can faith stand without the rule of truth. For he who has begun to deny the oneness of power in the Father and the Son and the Holy Spirit certainly cannot prove his divided faith in points where there is no division. So, then, since complete piety is to believe rightly, so complete impiety is to believe wrongly.