Chapter 25: Lord's Day 25
Section 65. Q. 65: It is by faith alone that we share in Christ and all his blessings: where then does that faith come from? A. The Holy Spirit produces it in our hearts by the preaching of the holy gospel, and confirms it through our use of the holy sacraments.
Section 66. Q. 66: What are sacraments? A. Sacraments are holy signs and seals for us to see. They were instituted by God so that by our use of them he might make us understand more clearly the promise of the gospel, and might put his seal on that promise. And this is God's gospel promise: to forgive our sins and give us eternal life by grace alone because of Christ's one sacrifice finished on the cross.
Section 67. Q. 67: Are both the word and the sacraments then intended to focus our faith on the sacrifice of Jesus Christ on the cross as the only ground of our salvation? A. Right! In the gospel the Holy Spirit teaches us and through the holy sacraments he assures us that our entire salvation rests on Christ's one sacrifice for us on the cross.
Section 68. Q. 68: How many sacraments did Christ institute in the New Testament? A. Two: holy baptism and the holy supper.