1 Chron 23:28-32 The duty of the Levites was to help Aaron's descendants in the service of the temple of the Lord: to be in charge of the courtyards, the side rooms, the purification of all sacred things and the performance of other duties at the house of God. They were in charge of the bread set out on the table, the flour for the grain offerings, the unleavened wafers, the baking and the mixing, and all measurements of quantity and size. They were also to stand every morning to thank and praise the Lord. They were to do the same in the evening and whenever burnt offerings were presented to the Lord on Sabbaths and at New Moon festivals and at appointed feasts. They were to serve before the Lord regularly in the proper number and in the way prescribed for them. And so the Levites carried out their responsibilities for the Tent of Meeting, for the Holy Place and, under their brothers the descendants of Aaron, for the service of the temple of the Lord.
In the episcopal system, we have the three-fold order of bishops, priests and deacons. Their roles correspond to the OT kings, priests and Levites. The bishops and the vicars (bishops' representatives in the local parishes) are the "kings", providing the overall leadership direction for the ministry. However, the priests (elders/pastors) are the ones who actually carried out the worship and word ministry similar to the OT priests. The deacons are like the Levites, providing the support ministries so that the main ministries of worship and the word can be carried out by the priests/pastors/elders.
In non-episcopal churches (Presbyterians, Baptists, AG, etc), we still have this same order, though the structures might not be like the episcopal church, viz., the overseers/moderators/superintendents may have less direct authority over the local congregational pastors. Even in such system, when the local congregations start planting sister congregations, the need for a overseeing leadership becomes an issue if the sister congregations choose to remain in fellowship with their sponsoring congregation.
So when churches start planting sister congregations, there will emerge a need for an overall overseer (traditionally called bishops or moderators). When that happens, the congregational pastors then function like priests assisted by deacons like the Levites supporting the Aaronic priesthood. However, the goal of this order is the ministry of the people to the Lord and ministry of the priests to the people. The structure resulting from this 3-fold leadership order is just a means to the end: ministry to God and people. Problem arises when the structure becomes an end rather than a means.
The organizations (structures) must not replace the people as the focus of ministry. We do not build the "church" as an organization but the "church" as individuals. The focus of ministry is building people, not starting institutions. When maintaining the integrity of the ecclesiastical organization (denominational structures and traditions) becomes more important than the ministry of the individuals, then it's time to review the forms of the organization. Forms must follow functions. The 3-fold order of leadership is given to serve the ministries to God and people. But we must not confuse the principle of the 3-fold order for leadership with a particular cultural practice of this principle. But too often in mainline churches, forms have greater priority over functions. When this happens, Jesus' word becomes relevant: new wine needs new wineskins (Mt 9:17; Mark 2:22; Luke 5:38). The forms (structures) should be adapted to the contexts of a particular culture, not adopted wholesale without considering the local contexts. But the principle of a 3-fold order of leadership remains unchanged.
Father, grant us wisdom to know when to adopt and when to adapt, so that our ministry to You and the people will not be compromised. Amen.