In this episode of The Priesthood, Fr. David Howell, diocesan priest from Southwark, England, recalls what the Catechism of the Catholic Church says: "The Eucharist is the source and summit of all Christian life." He emphasizes the importance of this sacrament and explains that the most important moment in history takes place in Holy Mass. Christ's sacrifice is made present in an invisible but real way. Fr. David expresses his gratitude to God for his great mercy and love for each and every soul because he has truly remained with us in the Eucharist. The priest celebrates Holy Mass to serve God's holy people.