Reference point for God’s existence is His Fatherhood – 3

“The Father derives from Himself His being, nor does He derive a single quality from another. Rather He is Himself the beginning and cause of the existence of all things both as to their nature and mode of being. All then that the Son and the Spirit have is from the Father, even their very being: and unless the Father is, neither the Son nor the Spirit is. And unless the Father possesses a certain attribute, neither the Son nor the Spirit possesses it: and through the Father, that is, because of the Father’s existence, the Son and the Spirit exist” (John of Damascus, De fide orthodoxa, I, 8, PG XCIV).