In today's reading there is a marvelous saying, in which we can sense all the joy of Israel at its redemption: "What great nation is there that has a god so near to it as the LORD our God is to us, whenever we call upon him?" (Deut 4:7).
Saint Thomas Aquinas took up this saying in his reflections for the Feast of Corpus Christi. In doing so, he showed how we Christians in the Church of the New Covenant can pronounce these words with yet more reason and more joy and with thankfulness than Israel could; in doing so, he showed how this saying, in the Church of Jesus Christ, has acquired a depth of meaning hitherto unsuspected: God has truly come to dwell among us in the Eucharist, He became flesh so that he might become bread. He gave himself to enter into the "fruit of the earth and the work of human hands"; thus he puts himself in our hands and into our hearts. God is not the great unknown, whom we can but dimly conceive. We need not fear, as heathen do, that he might be capricious and bloodthirsty or too far away and too great to hear men. He is there, and we always know where we can find him, where he allows himself to be found and is waiting for us. Today this should once more sink into our hearts: God is near. God knows us. God is waiting for us in Jesus Christ in the Blessed Sacrament. Let us not leave him waiting in vain! Let us not, through distraction and lethargy, pass by the greatest and most important thing life offers us. We should let ourselves be reminded, by today's reading, of the wonderful mystery kept close within the walls of our churches. Let us not pass it heedlessly by. Let us take time, in the course of the week, in passing, to go in and spend a moment with the Lord who is so near. During the day our churches should not be allowed to be dead houses, standing empty and seemingly useless. Jesus Christ's invitation is always being proffered from them. This sacred proximity to us is always alive in them. It is always calling us and inviting us in. This is what is lovely about Catholic churches, that within them there is, as it were, always worship, because the eucharistic presence of the Lord dwells always within them.
from Joseph Cardinal Ratzinger God is Nears Us: The Eucharist the Heart of Life