Westminster Confession of Faith
Chapter 30 -- Of Church Censures
1. The Lord Jesus, as King and Head of His Church, hath therein appointed a government, in the hand of Church officers, distinct from the civil magistrate.
2. To these officers the keys of the kingdom of heaven are committed; by virtue whereof, they have power, respectively, to retain, and remit sins; to shut that kingdom against the impenitent, both by the Word, and censures; and to open it unto penitent sinners, by the ministry of the Gospel; and by absolution from censures, as occasion shall require
3. Church censures are necessary, for the reclaiming and gaining of offending brethren, for deterring of others from like offenses, for purging out of that leaven which might infect the whole lump, for vindicating the honour of Christ, and the holy profession of the Gospel, and for preventing the wrath of God, which might justly fall upon the Church, if they should suffer His covenant, and the seals thereof, to be profaned by notorious and obstinate offenders.
4. For the better attaining of these ends, the officers of the church are to proceed by admonition, suspension from the sacrament of the Lord's Supper for a season; and by excommunication from the Church, according to the nature of the crime, and demerit of the person.