The Population Bomb Orders & Disorders To understand the change in Protestant thought and practice, we need to understand the Protestant vision of family and fertility, particularly as expressed by Luther and Calvin, and how it has changed over the last hundred years. Early sixteenth-century Europe was an era very different from ours. The late medieval Church claimed about one of every four adults in celibate orders, serving either as priests, nuns, or monks or in celibate military and trading groups such as the Teutonic Knights. Over the centuries, the religious orders had, through bequests, accumulated vast landed estates and gathered in the wealth that came through this ownership