Question: "What does the Bible say about the form of church government (polity)?"
Answer: The Lord was very clear in His Word about how He wishes His church on earth to be organized and run. First, Christ is the head of the church and its supreme authority (Ephesians 1:22; 4:15; Colossians 1:18). Second, the local church is to be autonomous, free from any external authority or control, with right of self-government and freedom from the interference of any hierarchy of individuals or organizations (Titus 1:5). Third, the church is to be governed by spiritual leadership consisting of two main offices—elders and deacons.
“Elders” were a leading body among the Israelites since the time of the books of Moses (the Pentateuch). We find them making political decisions (2 Samuel 5:3; 2 Samuel 17:4,15), advising the king in later history (1 Kings 20:7), and representing the people concerning spiritual matters (Exodus 17:5-6; 24:1,9; Numbers 11:16,24-25). The early Greek translation of the Old Testament (LXX) used presbuteros for “elder.” This is the same Greek word used in the New Testament that is also translated “elder.”
The New Testament refers a number of times to elders who served in the role of church leadership (Acts 14:23; 15:2; 20:17; Titus 1:5; James 5:14), and apparently each church had more than one as the word is usually found in the plural. The only exceptions refer to cases in which one elder is being singled out for some reason (1 Timothy 5:1, 19). In the Jerusalem church, they were part of the leadership along with the apostles (Acts 15:2-16:4).
Zodhiates, in his The Complete Word Study Dictionary: New Testament, defines this group of elders as follows: “The elders of Christian churches, presbyters, to whom was committed the direction and government of individual churches, equal to episkopos, overseer, bishop (Acts 11:30; 1 Timothy 5:17).” Thus, Zodhiates equates an “elder” to an overseer or bishop (as episkopos is translated). He sees the term elder as referring to the dignity of the office, while bishop or overseer denotes its authority and duties (1 Peter 2:25; 5:1,2,4). He notes that in Philippians 1:1, Paul greets the bishops and deacons but does not mention the elders (because the elders are one and the same as the bishops). Likewise, 1 Timothy 3:2, 8 gives the qualifications of bishops and deacons, but not of elders for the same reason. Titus 1:5 and 1:7 seem also to tie these two terms together.
Concerning the word pastor (poimen), in reference to a human leader of a church, it is found only once in the New Testament in Ephesians 4:11, “And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers.” Most associate the two terms pastors and teachers as referring to single individuals having both traits. Zodhiates, in his definition of poimen, states that the term pastor refers to the “spiritual guide of a particular church.”
There are two passages (Acts 20:28 and 1 Peter 5:1-2) that tie all three terms together and would seem to indicate that all three terms refer to one and the same office. As indicated above, deacons are a separate group of servants of the church and have a list of qualifications that are in many ways similar to that of bishop (1 Timothy 3:8-13). They assist the church as needed, as in Acts 6.
It would seem from the above passages that there was always a plurality of elders, but this does not negate God's gifting particular elders with the teaching gifts while gifting others with the gift of administration, etc. (Romans 12:3-8; Ephesians 4:11), nor does it negate His calling them into a ministry in which they will use those gifts (Acts 13:1). Thus, one elder may emerge as the “pastor,” another may do the majority of visiting members because he has the gift of compassion, another may “rule” in the sense of handling the organizational details, etc. Many churches that are organized with a pastor and deacon board perform the functions of a plurality of elders in that they share the ministry load (with deacons teaching Sunday School classes, etc.) and work together in some decision-making. In Scripture you will also find that there was much congregational input into decisions as well. Thus, a “dictator” leader who makes the decisions (whether called elder, or bishop, or pastor) is unscriptural (Acts 1:23, 26; 6:3, 5; 15:22, 30; 2 Corinthians 8:19). So, too, is a congregation-ruled church that does not give weight to the elders' or church leaders' input.
In summary, the Bible teaches a leadership consisting of a plurality of elders along with a group of deacons who serve as servants of the church. But it is not contrary to this plurality of elders to have one of these elders serving in the major “pastoral” role. God calls some as “pastor/teachers” (even as He called some to be missionaries in Acts 13) and gives them as gifts to the church (Ephesians 4:11). Thus, a church may have many elders, but not all elders are called to serve in the pastoral role. But, as a part of the elders, the pastor or “teaching elder” has no more authority in decision-making than does any other elder.