Two more points to add about infant baptism. Baptism is the rite we follow to bring someone into God’s family. In the Old Covenant, this was done on the 8th day with circumcision. We know that the New Covenant is better than the Old Covenant. So if in the Old children were entered into the covenant as infants, why would we have a New Covenant that was inferior and only allowed people to enter when they reached the age of reason? It’s not logical.
The second point is that in Acts it says that whole households were baptized. One can assume that included the children in those households. Otherwise it wouldn’t be the whole household. Certainly most of those baptized were adults, because everyone needed to be baptized. But, just like Abraham when God gave the Old Covenant, most of those who were circumcised were men because everyone needed to be brought in.
So infant baptism is not only valid, but expected given the Old Covenant.
Catholic Answers has three tracts on this subject: Early Teachings of Infant Baptism, Infant Baptism, and Born Again in Baptism.