33 So when their authority is abolished, His enemies shall be subjected: and so subjected, that He shall subject them to Himself. Moreover He shall so subject them to Himself, that God shall subject them to Him. Was the Apostle ignorant, think you, of the force of these words in the Gospel, No one comes to Me, except the Father draw Him to Me which stand side by side with those other words, No one comes unto the Father but by Me: just as in this Epistle Christ subjects His enemies to Himself, yet God subjects them to Him, and He witnesses throughout this, his work of subjection, that God is working in Him?
Except through Him there is no approach to the Father, but there is also no approach to Him, unless the Father draw us. Understanding Him to be the Son of God, we recognise in Him the true nature of the Father. Hence, when we learn to know the Son, God the Father calls us: when we believe the Son, God the Father receives us; for our recognition and knowledge of the Father is in the Son, Who shows us in Himself God the Father, Who draws us, if we be devout, by His fatherly love into a mutual bond with His Son.
So then the Father draws us, when, as the first condition, He is acknowledged Father: but no one comes to the Father except through the Son, because we cannot know the Father, unless faith in the Son is active in us, since we cannot approach the Father in worship, unless we first adore the Son, while if we know the Son, the Father draws us to eternal life and receives us. But each result is the work of the Son, for by the preaching of the Father, Whom the Son preaches, the Father brings us to the Son, and the Son leads us to the Father.
The statement of this Mystery was necessary for the more perfect understanding of the present passage, to show that through the Son the Father draws us and receives us; that we might understand the two aspects, the Son subjecting all to Himself, and the Father subjecting all to Him. Through the birth the nature of God is abiding in the Son, and does that which He Himself does. What He does God does, but what God does in Him, He Himself does: in the sense that where He acts Himself we must believe the Son of God acts; and where God acts, we must perceive the properties of the Father's nature existing in Him as the Son.
Source: On the Trinity (New Advent)