A Christian slave of Rome, Callistus was ordained by Pope St. Zephyrinus, whom he succeeded as pope in the year 217. As deacon he was guardian of the Christian cemetery on the Appian Way which is still known by his name. While he was vigorously opposed to heresy, his charitable attitude toward repentant sinners incurred the wrath of contemporary rigorists.
Mass of a POPE, except
O God, You see that we fail because of our weakness. Be merciful to us and let the example of Your saints renew our love of You. Through our Lord . . .
O Lord, may this sacramental offering help to free us of our sins and bring us to eternal salvation. Through our Lord . . .
O Almighty God, let these sacred rites cleanse us, so that through them we may lead holy lives. Through our Lord . . .