The Halfway Covenant was a form of partial church membership created by New England Puritans in 1662. It was promoted in particular by the Reverend Solomon Stoddard, who felt that the people of the English colonies were drifting away from their original religious purpose. First-generation settlers were beginning to die out, while their children and grandchildren often expressed less religious piety, and more desire for material wealth.
Full membership in the Puritan (and tax-supported) church required an account of a conversion experience, and only persons in full membership could have their own children baptized.
In response, the Halfway Covenant provided a partial church membership for the children and grandchildren of church members. Those who accepted the Covenant, and agreed to follow the creed and rules of the church, could become church members without claiming a spiritual experience. These half-members could not vote on any issues within the church, although all members could participate in the sacrament of the Supper.
Puritan preachers hoped that this plan would maintain some of the church's influence in society, and that these 'half-way members' would see the benefits of full membership, be exposed to teachings and piety which would lead to the "born again" experience, and eventually take the full oath of allegiance. Many of the more religious members of Puritan society rejected this plan as they felt it did not fully adhere to the church's guidelines, and many of the target members opted to wait for a true conversion experience instead of taking what they viewed as a short cut.
Overall, religious piety began to decrease and secular values began to become more prevalent in colonial society.
Response to the Halfway Covenant may have sown the seeds for the First Great Awakening in the 1730s, launched by Stoddard's grandson Jonathan Edwards. Along with Calvinist George Whitefield, he preached that God is "in the now", and there must be a "urgent call for lanquid will", in response to the half will that the Halfway Covenant allows.
Those who don't know history are destined to repeat it.