From Dom Eugene Boylan, O.C.R. in “This Tremendous Lover”, chapter 14: The Will of God as the Food of Christ.
By doing the will of God then we are formed into Christ, we are “digested” by Him, we are received into the roots and transformed into the vine. When we do the will of God, Christ, our High Priest, takes us into His hands, and blesses us, and says: “This is My Body,” and offers us up to His Father in Himself, and receives us into communion with Himself. The perfect union with Christ is to do the will of God for the love of God. There is nothing higher than that. Therein lies all holiness and all happiness; therein lies all that we may ever become, all that we ever dreamed of being; for it renews us in Christ and unites us to Him who is our God and our all!
The very words our Lord used show us His intention of handing over to us all His riches. This chalice is the new testament in my blood. And a ‘testament’ is a pact or agreement, for the disposal of our inheritance to be received. The Blessed Eucharist contains ‘those things which carry with them Christ’s relation to God the Father’ and all those things are at our disposal in the Mass.
And we are never more completely part of Himself than when we are doing the will of God.