St. John Vianney possessed a great devotion to the Eucharist, recognizing the reality that Jesus is truly present under the appearances of bread and wine.
There is a short prayer attributed to him that is simple yet profound. It is to be said before receiving Holy Communion, and asks Jesus to dwell within us.
It expresses the truth that God is coming to us in the Eucharist and that he desires to dwell within us, just as we desire to dwell within him.