From the first letter of Peter:
presbyters (presbuteroi in Greek) - often translated as 'elders' in English.
1 Peter 2: 4-9
4. Come to him, a living stone, rejected by human beings but chosen and precious in the sight of God,
5. and, like living stones, let yourselves be built 4 into a spiritual house to be a holy priesthood to offer spiritual sacrifices acceptable to God through Jesus Christ.
6. For it says in scripture: "Behold, I am laying a stone in Zion, a cornerstone, chosen and precious, and whoever believes in it shall not be put to shame."
7. Therefore, its value is for you who have faith, but for those without faith: "The stone which the builders rejected has become the cornerstone,"
8. and "A stone that will make people stumble, and a rock that will make them fall." They stumble by disobeying the word, as is their destiny.
9. But you are "a chosen race, a royal priesthood, a holy nation, a people of his own, so that you may announce the praises" of him who called you out of darkness into his wonderful light.
notes:
[4-8] Christ is the cornerstone (cf ⇒ Isaiah 28:16) that is the foundation of the spiritual edifice of the Christian community (⇒ 1 Peter 2:5). To unbelievers, Christ is an obstacle and a stumbling block on which they are destined to fall (⇒ 1 Peter 2:8); cf ⇒ Romans 11:11.
[5] Let yourselves be built: the form of the Greek word could also be indicative passive, "you are being built" (cf ⇒ 2 Peter 2:9).
[9-10] The prerogatives of ancient Israel mentioned here are now more fully and fittingly applied to the Christian people: "a chosen race" (cf ⇒ Isaiah 43:20-21) indicates their divine election (⇒ Eph 1:4-6); "a royal priesthood" (cf ⇒ Exodus 19:6) to serve and worship God in Christ, thus continuing the priestly functions of his life, passion, and resurrection; "a holy nation" (⇒ Exodus 19:6) reserved for God, a people he claims for his own (cf ⇒ Malachi 3:17) in virtue of their baptism into his death and resurrection. This transcends all natural and national divisions and unites the people into one community to glorify the one who led them from the darkness of paganism to the light of faith in Christ. From being "no people" deprived of all mercy, they have become the very people of God, the chosen recipients of his mercy (cf ⇒ Hosea 1:9; 2:23).
source:Copyright © Libreria Editrice Vaticanahttp://www.vatican.va/archive/ENG0839/_INDEX.HTM
1 Peter 5 1:2
I exhort the elders (presbuteroi) among you to tend the flock that is in your charge (kleros), exercising the oversight (episcope), not under compulsion but willingly, as God would have you do it.
Acts 20: 28
Keep watch over yourselves and over all the flock, of which the Holy Spirit has made you overseers (episcope), to shepherd the Church of God that he obtained with the blood of his own Son.