Much like how I defer to your knowledge of Judaism; somehow I’ve gone through life only meeting one practicing one, and two non-practicing ones. Well, I need to count you in there now, of course
A “believer’s baptism” (usually done full immersion), is those who reached the age of reason. They profess to believe in Christ, accept Jesus as their Lord and Savior, and use it as a means to enter into their community. If you were baptized as an infant, they sometimes request you get baptized again, because now you’re consenting to the baptism. This used to bother me, until I saw their point of view; they don’t think our Baptisms are valid due to lack of consent of the baby. Meanwhile, we don’t see theirs as conferring the same Graces through the use of the Sacrament, so they have to be baptized again (properly).
Some do “baby dedications” to cover the infants, a way of having the parents acknowledge they will raise their children in the faith. Some people even do “serial baptisms”. I’m not lying, my sister-in-law told me she had a friend who got “baptized” eight times. They’ll use baptism as a means to help boot strap themselves through tough times or as a re-commitment to Christ.
This of course all varies depending on the denomination. I used to primarily specialize in apologetics work with evangelicals (ironically due to an ex-girlfriend), so I’ve learned a few things here or there (and by “here or there” I mean a lot). Wikipedia has some decent information on “believer’s baptism” as well, if you ever want to do more reading on it.
Bringing things back to what Morgan asked, we can clearly see that there are distinct differences between the “evangelical” crowd’s believer’s baptism versus those who practice the Baptism that confers “Sacramental Graces” (ie; sanctifying grace and purification). So in that sense, I can see why the question was raised. There’s some far out notions of baptism. But there is the ONE Baptism for the forgiveness of sins misc etc, and if you have that it makes it easier to come home to Rome, because you have had the graces from THE Baptism already.