Religious training as a way of strengthening belief, has been an old approach, yet from around seventy years ago, it has been faced with some criticism in the West. Secular and pluralist critics claim that in religious trainings, understanding is neither the goal nor the outcome, because it is confession that is aimed at. Thus such religious trainings should be abandoned and replaced with un-confessional religious training or secular training in which instead of teaching a particular religion, lessons about all religions are taught. This very perspective is challenged herein by rereading the claim in the following three different ways: 1- religious understanding is impossible through religious training, 2- lack of understanding in religious exclusivism, and in 3- religious indoctrination, is necessary. Furthermore, through comparisons and criticism, it is said that: 1- being belief-based does not prevent understanding, 2- being exclusivist does not prevent understanding, 3- indoctrination is not subject-dependent, and religious training is not necessarily indoctrination. The Islamic approach to religious training is discussed where necessary.