The seven sacraments · Question 1.1
“A splash of water and your sins are gone? Isn't that magic?”

Baptism — a new life that begins with water
The Church's answer: The claim is not that the water itself has magical power. Baptism is a sacrament because Christ promised to set us free from sin and give us new life through the sign of water and the Holy Spirit. The fixed rite is not an incantation; it is a prayer in which the Church publicly proclaims the promise she has received.
If they press further: “If I'm baptized and then do something terrible, am I saved automatically?” — No. Baptism is not a license that cancels your freedom; it is the beginning of a new life, and the grace received has to be lived out in faith, repentance and love.
In one sentence: “Baptism isn't magic water — it's the sacrament in which Christ gives new life through water and the Holy Spirit.”