Book 4 of 4 - External Means by which God Invites Us into the Society of Christ and Holds Us Therein
Chapter 18 - Rome's Mass a sacrilege
19-20 - Conclusion - only two sacraments
19. Baptism is a single entrance into the church; the Supper is a repeated feeding. There are no other sacraments, since the promise of salvation is always attached to a sacrament.
20. We should be content with these 2. Israel had various sacraments: manna, water from the rock, the bronze serpent. But we have 2 unchanging ones, because the unchanging Christ has been revealed in these last days. So we are not to go inventing new doctrines or practices. We need to stick with the Word, which makes a sacrament a sacrament.