While still in England, the Puritans were typically treated very poorly. Puritans believed that the Church of England was the true church; however, they felt that it was in need of major reforms. The Puritans wanted to purify the Church of England by removing what they considered vestiges of Catholic excesses, corruption, and frivolity. In the 1600s, the Church of England and the English state were not separate entities. Therefore, criticism of the church was also considered criticism of the state itself. Consequently, the English authorities did not look too kindly on the Puritans, who they considered dissenters and sowers of division.
This resulted in the mistreatment of many Puritans. Beginning in the 1620s, the English government demanded that the Puritans conform to all official practices of the Church of England. When they did not comply, their ministers were forcibly removed from office. Puritans who continued to openly defy the authorities sometimes received very harsh punishments. For example, one Puritan who spoke out against the established religious practices in England was punished by having all his property seized, given a life sentence in jail, had his face mutilated, and was literally branded as a seditionist.
All this persecution convinced many Puritans that it was time to leave England. They hoped to create their own utopian society in the "New World," where they could freely practice their faith (meanwhile persecuting those who practiced differently) and show their fellow Englishmen and Englishwomen across the ocean that their path was the true path of God. That is why, in 1630, some twenty thousand Puritans left for a new life in America.