Pastors/elders are called, qualified men who are members of the church, tested and known, before they become elders. The congregation must know them to recommend them or speak to their character and maturity; likewise, the existing elders must know them to ascertain whether they are qualified and if they are called to meet the present need. Additionally, in every case in the New Testament where elders are appointed, apostolic men did the final appointing, and the consistent pattern is a plurality of elders. There is wisdom and safety in this New Testament design, wherein each man brings differing perspectives, gifting, abilities, and knowledge to bear in leading the church and caring for the flock they have been called to shepherd well.
Pastors are called to be shepherds, overseers, and elders who protect and feed the flock of God, rule well the household of God, and guide its people. Of course no earthly pastor is perfect. Like all of us, they fall short; they make mistakes, and yet they are called by God to a significant responsibility over His flock. Heeding that call, they eagerly, joyfully, and diligently work to know their members, to listen, to assess and meet their members
Deacons are qualified, gifted, responsible servants who do whatever is necessary to meet significant, practical needs in the church.
There are two types of discipline in the church. Foremost is formative discipline where God is teaching us through the church what is right. Second is corrective or restorative discipline, which is harder but sometimes necessary, for God's heart is to lose not even one of his sheep who goes astray but desires, rather, that they hear the truth and repent and are restored.