John Piper emphasizes that the New Testament teaches salvation by faith, citing verses like Acts 16:31, John 3:16, Ephesians 2:8, and Galatians 3:26. He explains that faith involves the heart, leading to a decision to accept Christ as Lord and Savior. Piper highlights the importance of confession with the mouth as an overflow of faith, referencing Romans 10:9 and Matthew 12:34. Additionally, he discusses the significance of baptism as an expression of faith and acceptance of Christ's Lordship, connecting it to the believer's death to sin and new life in Christ.

The New Testament teaches very plainly that we are saved by faith. "Believe on the Lord Jesus Christ and you shall be saved" (Acts 16:31). (Also John 3:16). "By grace you were saved through faith and that not of yourselves . . . " (Eph. 2:8). "For in Christ Jesus you are all sons of God through faith" (Gal. 3:26). The New Testament also teaches that faith is an act of the heart; it comes from the spring of our emotions and will. Romans 10:10 reads "With the heart man believes unto justification." We must decide to take Christ as our Lord and our Savior and we must love Him for the beauty of His holiness. But the transition from death to life, from darkness to light, from hopelessness to hopefulness, from slavery in sin to slavery to God is not merely a matter of ideas or emotions. It includes the whole person and therefore the New Testament calls not only for faith in the heart but also confession on the lips. "If you confess with your lips that Jesus is Lord and believe in your heart that God raised Him from the dead you will be saved" (Romans 10:9). Of course this doesn't mean that a person who is paralyzed and can't speak can't be saved. Such a notion would treat confession as a mechanical addition to faith. But Jesus said, "Out of the abundance of the heart the mouth speaks." (Mt. 12:34). Confession with the mouth is simply the overflow of faith. When Paul insists on confession he means: the heart must be full of faith and we must never limit life in Christ to a merely emotional or internal affair. To preserve this truth the New Testament calls for one more act in the process of passing from death to life, from alienation from God to reconciliation to God. Namely, Baptism. Jesus' final words to His disciples was: "Go make disciples of all nations, baptizing them in the name of the Father, the Son and the Holy Spirit, teaching them to observe all that I commanded you." So Peter concludes his first sermon after Jesus is gone with the words: "Repent and be baptized everyone of you in the name of Jesus for the forgiveness of your sins." Sometimes we refer to baptism as a symbol. That may be saying too little unless we remember that there are two ways to symbolize something. If you write the word LOVE on a blackboard for a group of 2nd graders and say that is the English language symbol for a commitment of the heart to someone's welfare, that's one kind of symbolism. But if you take your girlfriend out to a lagoon and sitting with her under a tree you pull a diamond ring out of your pocket and ask her to marry you and offer the ring as a symbol of your love, then you are doing something very different—you are expressing love through a symbolic action. The teacher who writes LOVE on the board need not have any love. But the giving of a diamond ring is love in action. Baptism is a symbol of faith in that second sense. It is an expression with the whole body of the heart's acceptance of Christ's Lordship. Why is this so fitting that Jesus commanded it of all His people? I think it is fitting because what happens in becoming a Christian involves the body as well as the heart. In conversion the heart is freed from sin to be enslaved to God. But in Romans 6 Paul really stresses that our bodies too are involved in this change over. For example, verse 13: "Do not yield the members of your body to sin as instruments of wickedness but yield yourselves to God as men who have been brought from death to life and your members to God as instruments of righteousness." It seems fitting that since the Lordship of Christ lays claim to our whole body, we should express our acceptance of that Lordship with an action of the whole body. And the action Jesus commanded is baptism. Baptism gives expression to our faith that we are God's from head to toe. The earliest church baptized by immersion and came to see this act as an acceptance of death with Christ and resurrection to new life. When the whole body goes under the water the believer symbolizes and expresses his desire that no aspect of his person escape death with Christ and renewal by His Spirit. I've been thinking about Bethlehem's baptismal pool. I've never seen anything like it. It is very much like a catacomb or a tomb. You enter through a small mouth and then it opens lightly here into a small room. The ceiling is very low (Rick will have to stoop). But this cramped tomb-like atmosphere is perhaps symbolically very appropriate. Paul said in Romans 6:3,4: "Do you not know that all of us who have been baptized into Christ Jesus were baptized into His death? We were buried therefore with Him by baptism into death so that as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life." So I've suggested to Rick and Marie, and Steve and Cindy that, as they enter that narrow door and move along the passage way into this pool, they let their movement signify their desire to die with Christ to sin and to walk in newness of life—life devoted wholly to God.