John Piper on baptism

I and my wife are discussing the baptism of our children. Eila was dedicated before my conviction on infant baptism. Asher has not been dedicated, outside our family, or baptized yet. As we discuss what baptism is and means I found this quote very interesting by John Piper.

Many of us came to faith and were baptized at a point when we did not know very much. This is good. It is expected that baptism happens early in the Christian walk when you do not know very much. So it is also expected that you will learn later more and more of what it means. Don’t think, “Oh, I must go back and get baptized again. I didn’t know it had all this meaning.” No. No. That would mean you would be getting re-baptized with every new course you take in Biblical theology. Rather, rejoice that you expressed your simple faith in obedience to Jesus and now are learning more and more of what it all meant.

Sounds like a good reason to baptize a child early on. They will grow in the grace that has been bestowed upon them. The most thought provoking question for me is where in Scripture is their a age limit on covenant inclusion?