When did the idea of “believers baptism” emerge in church history?
A. “Believers’ baptism” in the sense that children are excluded, seems to have arisen in the heretical Paulicians of Armenia in 1140 A.D. At least that was the finding of Church of Scotland scholars in their “Draft Interim Report in Baptism” p.32 (1959). It had its full expression in the Anabaptist movement, which had its origin in Zurich in 1523. They were called Anabaptists because they re-baptised those who had been baptised in infancy. It is a relatively modern idea.