51 Do you now perceive what it is to be the image of God? It means that all things are created in Him through Him. Whereas all things are created in Him, understand that He, Whose image He is, also creates all things in Him. And since all things which are created in Him are also created through Him, recognize that in Him Who is the image there is present the nature of Him, Whose image He is. For through Himself He creates the things which are created in Him, just as through Himself all things are reconciled in Him.
Inasmuch as they are reconciled in Him, recognise in Him the nature of the Father's unity, reconciling all things to Himself in Him. Inasmuch as all things are reconciled through Him, perceive Him reconciling to the Father in Himself all things which He reconciled through Himself. For the same Apostle says, But all things are from God, Who reconciled us to Himself through Christ, and gave unto us the ministry of reconciliation: to wit, that God was in Christ reconciling the world unto Himself. Compare with this the whole mystery of the faith of the Gospel.
For He Who is seen when Jesus is seen, Who works in His works, and speaks in His words, also reconciles in His reconciliation. And for this cause, in Him and through Him there is reconciliation, because the Father abiding in Him through a like nature restored the world to Himself by reconciliation through and in Him.
Source: On the Trinity (New Advent)