When the Puritans settled in New England, it soon became apparent that the whole European system of the parish church was going to be changed. According to the strict Calvinism they practiced (see Calvin, John, and Jacobus Arminius), people had to prove they had experienced new birth in order to be considered full, voting members of the congregation. This worked well in the first generation of New England Congregationalism (see Congregationalism). The people were already sifted by virtue of the fact that they had all immigrated for the same reasons. And since membership in the church was the requirement for voting in the parish, the pastor of the church being the town moderator, church and state were, for all practical purposes, one.
When their children were born it was understood that they were to be considered "half-way" members of the church, sealed by their baptism but not confirmed into full membership until they were old enough to demonstrate proof of Christian conversion. This was the established parish system. It was similar to the Jewish practice of circumcision. You were considered a "child of the covenant" because you were born to parents who were themselves members of the covenant.
But by the third generation, problems arose. Children were born to "half-way" church members, people who were baptized but had not yet demonstrated proof of conversion. What was the status of these children? Could they be allowed to vote in community matters?
Church members said no. Only full members should elect public officials. Such was the established pattern.
Non-church members called for disestablishment—the separation of church matters from civic concerns. They became known as "disestablishmentarianists."
Debate was heated because whatever decision was made would sacrifice a serious principle. If baptism and church membership were given to children of unregenerate parents, the church could no longer be considered a gathering of convinced believers. It would instead become a "mixed multitude," mocking the principles of Calvinism. But if baptism and church membership were denied, a growing number of people would be outside church discipline, and the whole dream of establishing a "Christian nation in the wilderness" would have come to naught.
This situation in 1657 prompted seventeen ministers from Massachusetts and Connecticut to meet in Boston and finally recommend that children of "half-way" covenanters be baptized. Charles Chauncey, president of Harvard College, virulently disagreed and headed up the opposition. The general court of Massachusetts eventually intervened in 1662, summoning a synod of churches to decide the issue once and for all. After a long debate, the Half-way Covenant was established. A person could be a voting member of the church and community simply by being baptized. One no longer had to exhibit proof of Christian conversion. And as long as a person's children were baptized and of legal age, they could vote, too.
Laxity resulting from the decision soon became apparent. When one domino fell, others followed. The Northampton Church began to allow children of unregenerate parents to take Communion. Two Harvard professors began to teach that all distinctions between regenerate and unregenerate believers be eliminated because such matters were a personal matter between the individual and God. The argument lasted for generations.
When the Salem witch trials began in 1692, some felt it was proof that God had deserted the people because they had opened the doors to sin and degradation. Others saw the whole disgusting episode as justification for the fact that the church has no business deciding civil matters in the first place.
Nowadays you can walk into a New England Congregational Church and just join up. In most cases they will welcome you with open arms and not even ask if your parents were ever baptized.