We see that grace can accomplish more than nature. If the words of Elijah had power to bring fire from heaven, will not the words of Christ have power to change the natures of the elements [of the bread and wine at the Eucharist]? You have read that in the creation of the whole world “he spoke and they came to be; he commanded and they were created.” If Christ could by speaking create out of nothing what did not exist, can we say that his words are unable to change existing things [the bread and wine] into something they previously were not [the body and blood of Christ]? It is no lesser feat to create new natures for things than to change their existing natures.

So the Church, in response to grace so great [as expressed in the Real Presence at the Eucharist], exhorts her children, exhorts her neighbors, to hasten to these mysteries: “Neighbors,” she says, “come and eat; friends, drink and be filled.” In another passage the Holy Spirit has made clear for you what you are to eat, what you are to drink. “Taste,” the prophet says, “and see that the Lord is good; blessed is the one who trusts in him.” Christ is in that sacrament [of Holy Communion], for it is the body [and blood] of Christ. It is therefore not bodily food but spiritual. Finally, it is this food that gives strength to our hearts, this drink which, “gives joy to the heart,” as the prophet has written.

—On the Mysteries 52-54

I love reading passages like these because they remind me that God continues to care and provide for us in quite tangible ways. That is why it is so important for us to feed on Christ in our heart with thanksgiving each week at the Eucharist, to let him strengthen and dwell in us in a tangible as well as spiritual way. This is a great mystery. It is also a great gift of love given to believers through grace and faith.