Support for the paedobaptist position relies heavily on the Old Testament since, as has been pointed out, no example of it can be found in the New Testament. Many point to passages like Acts 10:24-48, Acts 16:30-34, and 1 Corinthians 1:16, which mention the baptism of entire households. But the "entire household" argument is one made from silence, as there is never any mention of infants. In each instance, however, we can see that baptism followed belief in the gospel that had just been preached. I have a hard time picturing the disciples, in the middle of baptizing those who believed, saying, "While we're at it, let's take care of all the babies, too." With the exception of Jesus, baptism in the New testament is always preceded by repentance and faith.
Jesus ushered in a New Covenant that replaced the Old, so why this insistence that everything associated with Old Testament circumcision be carried over to New Testament baptism? Yes, all infants in ancient Israel were given the sign of the Old Covenant. And, yes, the unregenerate shared in the blessings of that covenant, even to the point of crossing over into the Promised Land. But scripture is quite clear who the members of the New Covenant are: those who have been born again.
What sealed the debate for me was what Paul wrote in Romans 6:1-4:
What shall we say then? Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it? Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.If we have already died (past tense) to sin, and baptism symbolizes our sharing in Christ's death and resurrection, then how, by any interpretation, does that apply to unregenerate infants?
I would agree with those who say that this is not an issue over which we should divide. After all, baptism is not the gospel. I do think, however, that friendly discussion and debate over issues like this is helpful when all of us share the goal of gaining a deeper understanding of scripture and a closer walk with Christ.