The Reformers are often charged with diminishing the potency of baptism. The opposite is the case.
George Huntston Williams (article in Church History, 1957) notes the gradual “depression and routinization of baptism” in the early medieval period, a process that he says was nearly complete by the 11th century. Baptism diminished as and because penance rose to become “a second plank of rescue after baptism” and “a rite of public humiliation in the presence of the more steadfast believers.”
In rejecting penance, the Reformers put all the weight back on baptism. According to Luther’s Larger Catechism, “Baptism, both in its power and signification, comprehends also the third Sacrament, which has been called repentance, as it is really nothing else than Baptism. For what else is repentance but an earnest attack upon the old man [that his lusts be restrained] and entering upon a new life? Therefore, if you live in repentance, you walk in Baptism, which not only signifies such a new life, but also produces, begins, and exercises it. For therein are given grace, the Spirit, and power to suppress the old man, so that the new man may come forth and become strong. Therefore our Baptism abides forever.”
Of Anselm, Williams writes, “Baptism, from having been the unique sacrament of incorporation in the body of Christ in the ancient Church, was in Anselm demoted to serving as the ablutionary preparation therefor, or at best was regarded as a contingent incorporatio imperfecta to be followed by eucharistic incorporatio perfecta.”
Protestants made baptism more, not less effective than Catholics.