A formal, written agreement by which Christians commit themselves to a particular local church and to one another in covenanted relationship. The practice is strongest in the Baptist and Congregational traditions. A typical church covenant articulates mutual commitments: to meet regularly, to pursue mutual edification, to practice church discipline, to give financially, to uphold sound doctrine, to bring up children in the faith, to reach the lost, to walk with integrity, and to watch over one another in love. The covenant is usually read aloud in the congregation, especially at communion or new-member services.
Church membership in the NT is covenantal, not consumer. The early Church "added daily such as were being saved" (Acts 2:47) — added to a body with definite boundaries, not a free-floating "network." The practice of formal church covenants flowered among 17th-century Puritans and Particular Baptists, who saw covenanting as the proper response to discovering you are part of the covenant community of Christ. The most famous historic example is the 1640 Baptist covenant of the Horton church (England), but virtually every healthy Baptist church has some form of covenant. Modern evangelicalism has largely lost this. People "attend" churches as spectators or consumers; they shop around, leave when offended, and never submit to congregational life or discipline. The recovery of church covenants is part of the broader recovery of church membership and discipline pioneered by writers like Mark Dever, Jonathan Leeman, and John Piper. A church covenant does not save — but it does create clarity. You know what you are committing to; the church knows how to hold you to it. Both are needed.