Blessed Father Eustace cultivated a profound devotion to the Sacred Heart of Jesus, which permeated his entire life and priestly mission. A member of the Congregation of the Sacred Hearts, he saw in the Heart of Jesus the inexhaustible source of love and mercy for humanity.

“"Heart of Jesus, ocean of goodness, perennial fountain of mercy, deign to hear my prayers."”

In his writings, Father Eustace emphasized that the principal devotion of a Christian should be to love Jesus Christ. He recalled the revelations of Jesus to Saint Margaret Mary Alacoque, in which the Lord expressed the desire that His Heart be honored with a special devotion, to repair the offenses received in the Sacrament of the Eucharist.

“We possess the living, pulsating reality of His love. That living Heart which was the first continent and engine of Jesus” organic life, we possess it.”