The more reformed I get, however, the more I believe everything is determined by His will and purpose. And it is God who gives us our children. I don't believe He does that carelessly, but with perfect intent and result.
Are some baptized children of true believers reprobates?
I don't know. All we have is His promise to us and to our children. And if the promise to us is sure and true, then so is His promise to our children...one way or another.
Here's the great site, A Puritan's Mind, and its author, Dr. Matthew McMahon, who was a Baptist pastor who came to believe in the truth of infant baptism a decade ago...
I think it's well worth the read.
That's the center of the argument. If Baptism imparts Grace then it is a salvational issue.
Are some baptized children of true believers reprobates?
We just don't know, but as an example what about Charles Manson. Was he baptized as an infant? It's probably a pretty good bet he's going to hell.
Just as we are commanded to preach the Great Commission, we are commanded to be baptized. This doesn't make you holy or better than anyone else, it brings you the blessing of obedience.
Though I'm sure parents mean well and think that they are baptizing their infants, truly they are not. The baby of believers unfortunately, is no more holy, or even elect, than the baby of unbelievers. Perhaps he or she does have a measure of divine protection, but it is up to the individual alone to repent and make a confession of Christ. The church can't do it for you and your parents can't do it for you.
There is a whole nation today of baptized unbelievers, but the truth is they were never baptized, not according to the New Testament anyway. Their parents thought the rite was some sort of voodoo and would protect them. If they are unregenerated then they are still unsaved.
Note also that "Jesus came up out of the water" and the theological implications go deeper as we have privately discussed before.