Baptism is important according to our Catechism 1213 it says:
“Holy Baptism is the basis of the whole Christian life, the gateway to life in the Spirit (vitae spiritualis ianua),4 and the door which gives access to the other sacraments. Through Baptism we are freed from sin and reborn as sons of God; we become members of Christ, are incorporated into the Church and made sharers in her mission.”
The thing about Baptism is that once someone has been baptized they are now obligated to live a life in communion with the church.
As Catholics we are obligated to attend mass every Sunday, Get married in the Church, faithfully receive the sacraments, and live our lives in accordance with the social teachings of the Church.
I think that a lot of people nowadays treat Baptism as if it’s a party…kind of like a baby shower or a sweet 16 birthday. They don’t understand that through our Baptism we now have life long obligations to live as faithful Catholics.
So in your example of the church refusing to baptize the atheist’s baby…How can the church take part in such an arrangement in which they know that the child will not be taught according to the Catholic faith? It’s not something to be taken lightly. The atheist parents in your example are treating Baptism as a “Right of Passage.” Whereas in the churches eyes this child will be a baptized Catholic who most likely will not attend mass (a Sin), deny the existence of God (a heresy) and live a life that is not in communion with the church in which they have been baptized. Their faith will not develop. To treat the sacrament in this manner is to denigrate this holy gift from God into just a party.
In fact what type of creed will this child be taught at the hands of their atheist parents?
“I (don’t) believe in God, (there is no) father almighty, (there isn’t) maker of heaven and earth…”