The Baptism of John - Mat 3:1-17

In preparation for my Sermon on Matthew 3:1-12 The Urgency of the Kingdom, this morning when I went for my morning run, I listened to John Piper preach on Matthew 3:1-17. His message was mainly about Baptism, though. Which I was not going to talk too much about, that after this sermon, it might be appropriate.
A Few points I want to remember from his sermon are:

1. Baptism is not a denomination thing, it is a Church thing! In the Bible apart from the thief on the cross in Luke 23:43, there are no unbaptized believers!
2. Case for altar calls - people aren't to be anonymous, what if there was an answer through faith to the message being preached? Paul seemed to be aware of who those people were in Acts 14:4,12,34)
3. Baptism is the public way, of affirming our faith. 
4. There is a close continuity between John's baptism and Christian baptism. John Baptized, Jesus baptized, and he commanded the church to baptize. 
5. When a Jewish person received John's baptism, it was a radical act of individual commitment to belong to the true people of God, based on personal confession and repentance, NOT on corporate identity with Israel through birth.
6. Case against infant baptism: John's baptism is associated with commitment to a changed life as opposed to becoming part of the people of God through your birth. People who had the sign of the Covenant were told to change their lives and be baptized. How can we then make of baptism the new sign of the Covenant that we receive at birth, if it seemed to be attacking that! Being born into a covenant family was no guarantee of being a child of God. Baptism is John's new sign of belonging of the true people of God : not based on Jewishness or being born into a covenant family, but based on radically personal, individual repentance and faith.
7. John's baptism was radical, because it was adressed to the Jews, who thought they were already save through the Jewish heritage. 
8. God will fulfill his promises because he does not lie! But Jews must not assume that God needs them to fulfill those promises. He can easily raise new children of Abraham. 
9. John's baptism is not a continuation of circumcision. It was an indictment of a misuse of circumcision as a guarantee of salvation. Circumcision was a sign of ethnic continuity; baptism was a sign of spiritual reality.
10. Baptism is for those who believe.
11. Until AD 200 with Tertullian, there is no mention of infant baptism. 

Piper's Conclusion: 

"The way of salvation is repentance and faith in Christ, not ethnic identity or birth to Christian parents. God calls us today, no matter who our parents were, and no matter what ritual we received as infants : God calls us today to repent and believe on Christ alone for salvation and to receive the new sign of the new covenant of the people of God : the sign of repentance and faith, baptism. So I call on every one of you who has not followed Christ in this way, "Repent and be baptized" (Acts 2:38). This is the call of God. This is the path of obedience and life."