The following is an excerpt from Systematic Theology: A Compendious View of Natural and Revealed Religion by John Brown of Haddington. Read online.
In preaching the gospel, and administering the sacraments, ministers exercise their power as single persons. But all jurisdiction relative to admission of members, ordination of officers, censure of offenders, or absolution of penitents, is to be exercised socially, in courts constituted of two or more rulers, in the name of Jesus Christ,—viz. in Sessions, Presbyteries, and Synods.
I. Sessions are church courts constituted of the rulers of a particular congregation. Their appointment by Christ is evident. 1. The light of nature teaches us to decide smaller matters by inferior courts, Exod 18:17-23. 2. The Scripture approves of judging lesser matters by inferior courts, Exod 18:17-26; Matt 5:22; Matt 18:17-20. 3. In the form of process against scandals, prescribed by Christ, there is a plain allusion to the courts of the Jewish synagogues or congregational assemblies, Matt 18:15-18. 4. In conformity to the Jewish synagogues, every Christian congregation hath several elders allotted to it by God’s warrant, Mark 5:35-38; Luke 8:41; Luke 13:14; John 9:22; Acts 13:15. Acts 18:8,17; Acts 14:23; Titus 1:5. 5. Necessity requires such courts; it being impossible for every thing proper to be judged in congregations, to be got carried to presbyteries and synods.—It belongs to sessions to inquire into the spiritual state or Christian characters of members of the congregation; to admit members to, or suspend them from sealing ordinances; to admonish and rebuke offenders, or absolve them when penitent.
II. Presbyteries are church-courts constituted of different pastors, and ruling elders from different congregations.—Such courts are warranted by Christ.
1. Many affairs of the church, as trial, and ordination of pastors; judging subtle heretics; composing differences in sessions, or between different congregations, require such courts, Rom 14:19; 1 Cor 14:26,40.
2. The strict connection of Christians in one mystical body of Christ, requires that unity of fellowship among them should be carried as far as possible, Rom 12:5; Eph 4:3- 6; 1 Cor 12:12,27.
3. There is an express mention of a presbytery at the ordination of Timothy, 1 Tim 4:14.
4. The Scripture exhibits several patterns of one presbytery governing several particular congregations of Christians, 1. At Jerusalem three thousand were added to one hundred and twenty members of the then forming church, and others daily adding, Acts 1:15; Acts 2:41,47. Five thousand were afterwards added to them, and thereafter such multitudes, that the twelve apostles, on account of their preaching the gospel, had not time to receive or distribute their charity to the poor. To all these were added a great number of priests, and, no doubt, others obedient to the faith, Acts 4:4; Acts 5:14; Acts 6:7. All these taken together could scarcely be fewer than forty thousand.— Notwithstanding repeated persecutions, Acts 8; Acts 12, we find them many ten thousands, Acts 21:20; which could scarcely be fewer than forty or eighty thousand. Now, in what private house, and they had no other place, could all these assemble to eat the Lord’s Supper together.—The twelve apostles, with several other teachers, laboured ordinarily at Jerusalem, for many years, and preached the gospel in different languages. Now, how absurd to pretend, that they did all this in one single congregation, Acts 2:41-42; Acts 4:31-37; Acts 6:2; Acts 8:14; Acts 15:2; Acts 2:5-12?—Nevertheless, all the Christians in and about Jerusalem are represented as one church, the rulers of which met together for acts of government, Acts 11:27,30; Acts 15:2; Acts 6:1-6; Acts 21:18. 2. At Antioch a great number believed and afterward much people was added to the Lord, Acts 11:24,26. They had a great number of teachers, Acts 11:20,23,26; Acts 13:1-3; Acts 15:35. How could such multitudes amidst persecutors find one place fit to contain them, in their eating the Lord’s Supper? Or, how could so many teachers find work in one single congregation? Nevertheless, they are all called one church, Acts 13:1-3; Acts 15:35. 3. At Ephesus the word of God grew mightily and prevailed. A multitude even of magicians believed, and burnt their devilish books to the value of fifty thousand pieces of silver, Acts 19:10,17-20; 1 Cor 16:8-9. They had Paul, and twelve other teachers, that prophesied at once; and afterwards a considerable number of presbyters or bishops, Acts 19:1-10; Acts 20:17,28,36. —Nevertheless, all these Christians of Ephesus belonged to one church, the rulers of which are represented as one Angel, and met to judge their spiritual affairs, Rev 1:11; Rev 2:1; Acts 20:17,28. 4. At Corinth many believed; the Lord had much people, Acts 18:8-10. They had a considerable number of teachers that taught in different languages and churches, 1 Cor 14:20,26,29,32,34. Nevertheless, all the Christians at Corinth were but one church, the rulers of which met together for government, 1 Cor 1:2; 1 Cor 5:4,13; 2 Cor 2:6,9. In none of these places had they then any diocesan bishops, as their uniting heads.
III. Synods are church-courts constituted of several presbyteries, in order to review their sentences when necessary, and to regulate affairs which are too hard for presbyteries, or which affect different presbyteries. The divine warrant for synods appears, 1. From the ecclesiastical sanhedrim of the Jews, which had the supreme power in excommunications, etc. 2 Chron 19:11; Matt 18:18. 2. From the greater safety of extensive consultation, Eccles 4:9; Prov 11:14; 1 Cor 14:32. 3. From the law of necessity in some cases,—as when a whole presbytery or their people are infected with error or scandal; or when disputes arise between different presbyteries. 4. From the unity of the church, Matt 16:18; 1 Tim 3:15; Eph 4:4-12; 1 Cor 12; 1 Cor 10:32. 5. From the pattern of the apostolical synod, Acts 15. Here was a proper case for the decision of a synod;—a dispute which could not be composed by the presbytery of Antioch, and which concerned not only the churches of Syria and Cilicia, but also of Jerusalem,—from which the raisers of it pretended to derive their authority. Here the proper members of a synod were convened,—Apostles and elders at Jerusalem, with others deputed from the churches of Syria and Cilicia,—who all, as on the same level, judged, Acts 15:2,6,22-36; Acts 16:4.—As it was impossible for all the believers in Jerusalem to meet in this synod, we are uncertain if the brethren mentioned in the history of it means any but preaching elders, Acts 15:22; but we grant that such private Christians as were present signified their consent, and even voted in the election of the commissioners that were to bear the letters of the synod to the churches of Syria and Cilicia, etc.—Here, as in a synod, the Apostles and elders, by reasoning from facts, and especially from the Scriptures, prepared the affair for a decision.—In the decision itself the whole power of a church synod was exercised. The true doctrine was solemnly asserted and declared; the erroneous were publicly stigmatized; and a decree of decency and order was established.—The whole decision was authoritative, not mere consultation, and hence is called a necessary burden imposed,—decrees ordained;—and as such was cheerfully submitted to by the churches concerned, Acts 15:28,31; Acts 16:4-5; 1 Thess 5:12; 1 Cor 16:16; Heb 13:7,17.
The subordination of sessions to presbyteries, and of presbyteries to synods, is manifest, 1. From the very light of nature, which requires the subordination of the lesser to the greater. 2. From the gradation prescribed by Christ in the removing offences, Matt 18:15-18. 3. From the reference made by the churches of Syria and Cilicia to the Synod at Jerusalem, Acts 15:4. From the absurdities which follow on the denial of it, as that no relief is left by the law of Christ for one that is injured by the greater part of a congregation, session, or presbytery;—that no means are left for the reclaiming a greater part of a congregation, session, or presbytery,—nor any means of promoting uniformity between sister congregations. 5. From a consideration of the peculiar advantages of presbyterian government. 1. It best restrains the lordly pride of clergymen. 2. It best secures liberty and peace to the people. 3. It best brings offenders to adequate censure. 4. It most effectually answers the purging out of error. 5. It is best calculated to prevent schisms and separations.
John Brown of Haddington, Systematic Theology: A Compendious View of Natural and Revealed Religion, Book VII, Chap. 3