Anabaptists. Quakers, Hutterites, Amish, Mennonites, Brethren mostly. Wikipedia has a good summary:
Anabaptists (Greek ανα (again, twice) +βαπτιζω (baptize), thus "re-baptizers"[1]) are Protestant Christians of the Radical Reformation of 16th-century Europe, and their direct descendants, particularly the Amish, Brethren, Hutterites, and Mennonites.
Anabaptists rejected conventional Christian practices such as wearing wedding rings, taking oaths, and participating in civil government. They adhered to a literal interpretation of the Sermon on the Mount and believer's baptism.
The name Anabaptist is derived from the Latin term anabaptista, or "one who baptizes over again", in reference to practicing adult baptism, because, as a new faith, they baptized converts who already had been baptized (as infants) in the older Christian churches.[2]
Anabaptists required that candidates be able to make their own confessions of faith and so refused baptism to infants. As a result, Anabaptists were heavily persecuted during the 16th century and into the 17th by both other Protestants and Roman Catholics.
Sorry, no mention of gunsmithing.