Augustine explains Jesus’ teaching that eating his flesh and drinking his blood brings life and makes believers dwell in him. The words must be understood spiritually rather than carnally: union with Christ requires remaining members of his body with him as their head. To abide means persevering in faith to the end, including through suffering and death. Saint Laurence illustrates this perseverance, receiving strength through the Eucharist to endure torture. The tractate presents the martyrs’ union with Christ as their comfort and victory in the hope of eternal life. Augustine therefore joins Eucharistic teaching to perseverance, explaining how spiritual participation in Christ sustains believers when bodily suffering becomes severe today.