Historians generally explain the perceived decline in religious fervor among Puritans to a few key factors. For one thing, many Puritan families, especially those whose presence in New England dated to its founding, had become quite affluent, and the sense of communalism that was so important to the Puritan ethic declined. Many became focused on the acquisition of worldly goods rather than the asceticism that characterized early generations of Puritans who had more of a sense of religious mission.
More important, the colony had grown very rapidly, which affected religious fervor inasmuch as many people who moved to the colony were not actually Puritans. While Puritans dominated the politics and society of New England colonies, the colony's diversity tended to weaken the notion of a religious "city on a hill." Moreover, as people moved away from the coast and began new towns, they struggled to find ministers to tend to new churches. Young people in particular tended to lack the sense of religious orthodoxy that their parents had. This was one of the reasons the Puritans enacted the so-called "Halfway Covenant" that allowed people who had not experienced conversion experiences (formerly essential for church membership) to have their children baptized.