That would be because salvation is through faith in Christ, not of works. Baptism has been elevated to a work in many churches, not just the Catholic one.
It does not detract from the necessity of baptism if you believe that baptism is necessary for salvation and that one is not held accountable is one has not sinned. Some churches maintain that baptism is necessary for salvation AFTER the person has made their own profession of faith. That inflicting baptism on someone cannot save them.
RNMomof7 is right. It is a kind of election, only by the parents and the church, not by God.
I’m content to follow Paul who tells us in 1 Corinthians 7 that the children of one believing parent are holy, and that even the unbelieving spouse of a believer is holy to God.
That’s an amazing statement for Paul to make. It must be because Paul realizes God gives us our children and our spouse, and He does that in love. Therefore, because God loves the believer, He will cover the believer’s family with His grace.
That’s enough assurance for me. That tells me that while my responsibility is to raise strong Christians who kneel to none but Christ I have His promise that He will not let the feet of my children slip so far away that they will not be brought back to Him.
One way or another.
Christians need to rejoice in this promise. It was given to us to strengthen us and keep us focused on Christ from whom all blessings flow.