The manner of our indwelling in Him through the Sacrament of His Body and Blood is evident from the Lord’s own words: This world will see Me no longer but you shall see Me. Because I live you shall live also, for I am in My Father, you are in Me, and I am in you. If it had been a question of a mere unity of will, why should He have given us this explanation of the steps by which it is achieved? He is in the Father by reason of His divine nature, we are in Him by reason of His human birth, and He is in us through the mystery of the Sacraments. This, surely, is what He wished us to believe; this is how He wanted us to understand the perfect unity that is achieved through our Mediator, who lives in the Father while we live in Him, and Who, while living in the Father, lives also in us. This is how we attain to unity with the Father. Christ is in very truth in the Father by his eternal generation; we are in very truth in Christ, and He likewise is in us.
St Hilary, bishop of Poitiers
May God bless all who read my ramblings,