In nearly all evangelical church, you would find a pastor (or pastors) and elders. In some, both are able to work well together; but in others, they are constantly at odds with one another – most of the time, it is the elders who are trying to have the last say in the matters of the church. This, I believe, is the result of an improper understanding of the role of elders in a church. Having worked in a church – a few, as a matter of fact – I became concerned and curious to find out what the Bible says about it.
The New Testament uses several words to refer to the office of elder. Most commonly, episkopos and presbuteros are used; these words are usually translated bishop or overseer, and elder or presbyter respectively. Another word, poimen, is found less frequently even though its translation, pastor, is a common English word used in churches to refer to this office. Importantly for our discussion, the New Testament uses these words interchangeably. 
Therefore, the bishop, overseer, elder, presbyter, and pastor have the same role in the church since these terms are used interchangeably in the New Testament.
Obviously, in the early church, there were no full-time pastor like we have today. The only so-called “full-time” workers were Paul, Timothy, Titus and Silas. The last three were, as you know, apostles-in-training. At times, they were tasked to identify and appoint elders in the church (See Titus 1:5). To help them with this task, Paul gave them a list of qualifications to follow and they can be found in 1 Timothy 3:1-7 and Titus 1:5-9. These lists are identical and there are two things which I would like to point out to you.
First, Timothy and Titus were to look for men, good Christian men; not women. Second, whether or not a man is qualified to be a elder of a church depends on how he fares in his family and in the world – for example, he must be “above reproach, the husband of one wife, sober-minded, self-controlled, respectable, hospitable,” etc. There was no training to prepare someone for eldership.
Once these elders were appointed, Paul takes a step back and lets them do their work. The duties of an elder are as follows:
THE DUTIES OF AN ELDER
- Elders are asked to do many things:
- Pray and study Scripture (Acts 6:4).
- Rule/lead the church (1 Tim. 5:17).
- Manage the church (1 Tim. 3:4–5).
- Care for people in the church (1 Pet. 5:2–5).
- Give account to God for the church (Heb. 13:17).
- Live exemplary lives (Heb. 13:7).
- Rightly use the authority God has given them (Acts 20:28).
- Teach the Bible correctly (Eph. 4:11; 1 Tim. 3:2).
- Preach (1 Tim. 5:17).
- Pray for the sick (James 5:13–15).
- Teach sound doctrine and refute false teachings (Titus 1:9).
- Work hard (1 Thess. 5:12).
- Rightly use money and power (1 Pet. 5:1–3).
- Protect the church from false teachers (Acts 20:17–31).
- Discipline unrepentant Christians (Matt. 18:15–17).
- Obey local, state, and federal laws (Rom. 13:1–7).
- Develop other leaders and teachers (Eph. 4:11–16; 2 Tim. 2:1–2).
Pastors and Elders
In most churches today, there are full-time pastors as well as elders. This is where things get quite complicated. What is the difference between a pastor and an elder? The more important question, it seems, is: “Who is above who?” In some churches, elders see themselves as the “board of directors,” who are responsible to set the course of the church, form policies and determine strategies; leaving the pastor to execute them. This, in my opinion, is inappropriate for the simple reason that the pastor (or pastors) are full-time workers – having received the call of God to dedicate their entire lives to the ministry – whereas the elders are “lay” people. When an elder is challenged to enter full-time ministry, he would immediately tell you, “I am not called”. And he is right. But it is precisely because he is not called that he does not have the same spiritual authority that a pastor who has been called by God. And elder, as seen throughout the New Testament, is appointed – not called, and least of all elected. And because he was appointed, he can also be un-appointed. There is not such thing as “an elder for life”.
From the way the Levitical Priesthood was organized, we can learn a principle or two. First, not everyone in the priesthood are equally holy. The high priest is the holiest, followed by the priests and then the Levites. In the same way, there is a certain hierarchy within the church: God has appointed first apostles, second prophets – who are the foundation of the church – and followed by the evangelists, pastors and teachers, otherwise known as the Five-fold Ministers (1 Cor 12:28, Eph 2:20 and 4:11-12).
The elders of the church are, therefore, pastors. The only difference between them and the pastor is that they are not serving in a full-time capacity. In such a case, the full-time pastor ought to fulfill a more apostolic role (not be an apostle). By this, I mean that he is the one who leads the church in accordance to what hears from the Lord, and teaches and preaches to edify and equip the members of the church for ministry.
As (lay) pastors, elders are directly ministering to the flock. They might be leaders of small groups or heading various ministries in the church. They are always available to visit and pray for the sick. When the elders are doing their work as they should, the church would not need to hire many full-time pastors.
Elders also serve the pastor, just as the Levites were commanded to serve the priests (Num 3:9). They serve the pastor by praying for him and encouraging him in various ways. They may offer their advice or suggestions to the pastor on church matters, but they should not override him through a vote.
 Sojourners and Strangers. Gregg Allison. p.211
 The Resurgence http://theresurgence.com/2012/07/11/what-is-a-church-elder