The ordinary way to salvation, to heaven is Baptism. Yet, God can provide extraordinary means of salvation, known to Him alone. The universal Catechism teaches that “God has bound salvation to the sacrament of Baptism, but he himself is not bound by his sacraments.” (CCC, no. 1257)The extraordinary means of salvation that only God knows and can provide do not undermine the necessity of Baptism, as a sure means to salvation. (See CCC, no. 1257)
If Jesus himself instituted the Sacrament of Baptism as an ordinary means of salvation, why would one who knows this truth, refuse to be baptized or refuse that his/her child be baptized in the Catholic Church?
Certainly, unbaptized babies cannot be punished in hell because they have not committed any mortal sins. They cannot go immediately to heaven due to inherited original sin, which is remitted at Baptism. They can’t be in purgatory as well because they have not committed any personal sins that require purification.
Will they go to limbo? The doctrine of limbo is not a Church dogma but a theological opinion. Theological opinion means that the doctrine comes from the teaching of theologians not from the official teaching of the Catholic Church, the Magisterium. Thus, the doctrine of limbo does not demand the assent of our faith. In other words, we will not commit sin if we refuse to believe in it.
Where then will they go? The Catechism of the Catholic Church replies: “As regards children who have died without Baptism, the Church can only entrust them to the mercy of God, as she does in her funeral rites for them. Indeed the great mercy of God who desires that all men should be saved, and Jesus’ tenderness toward children which caused him to say: “Let the children come to me, do not hinder them,” allow us to hope that there is way of salvation for children who have died without Baptism. All the more urgent is the Church’s call not to prevent little children coming to Christ through the gift of holy Baptism.” (CCC, no. 1261)