Book 4 of 4 - External Means by which God Invites Us into the Society of Christ and Holds Us Therein
Chapter 14 - The Sacraments
14-17 - Sacraments don't impart grace of themselves, but hold forth Christ
14. So, the view that sacraments attest our faith "overthrow[s] their use." Rome, on the other hand, gives sacraments "some sort of secret powers," saying they "justify and confer grace." This is "diabolical," and offers "a righteousness apart from faith." You can't expect anything in the sacrament apart from God's promise, but that promise "offers grace to believers." We have assurance of salvation in the Word - sacraments are not necessary to our assurance.
15. We have to distinguish between the actual grace we have in Christ, and the sign of it in the sacrament. "The sacraments effect what they represent" in the elect, Augustine said. It "was poison to Judas." "A sacrament is thus separated from its truth by the unworthiness of the recipient."
16. "Christ is... the substance of all the sacraments." Man can't void the sacraments' effectiveness by his infidelity. It remains spiritual but the unbeliever gets no benefit. We should avoid deprecating the outward sign, and avoid fixating on it instead of on Christ.
17. The sacraments have the same function as the Word: to "set forth Christ to us." God is present in the sacraments; the question is if He gives His power over to the outward symbols (He doesn't), or if they work by His power (yes).