According to Luther’s Small Catechism, baptism is a sign that:
“the old person in us with all sins and evil desires is to be drowned through daily sorrow for sin and repentance, and that daily a new person is to come forth and rise up.”
Baptism is the moment of our incorporation into the crucified and risen body of Jesus, a time when Christ takes hold of us and makes us His. It is entirely a work of God’s grace, as it is He alone who works faith in our hearts through the Holy Spirit. Since a human “decision” is not the beginning of our life as God’s child, Lutherans baptize infants. In the sacrament of baptism, through water and the Word, we become the sheep of His pasture. He calls us by name. I’ve always associated baptism with this children’s hymn I used to sing with my daughters. Listen closely and you’ll see it addresses our end as well as our beginning.