1 Peter 2:25

ἦτε γὰρ ὡς πρόβατα πλανώμενοι (T.R. πλανώμενα). St Peter means, You Gentiles may well apply to yourselves the language of Isaiah 53 about those healed by the suffering Servant of the Lord, for you were indeed wandering like lost sheep, as the speakers in that chapter describe themselves.

ποιμένα καὶ ἐπίσκοπον. The Shepherd and overseer or guardian who was all along watching over your lives. You were all along His sheep though previously “not of this fold,” cf. John 10:16, your conversion may therefore be described as returning to Him.

For ποιμήν applied to Christ, cf. John 10:11; 1 Peter 5:4; Hebrews 13:20; cf. Revelation 7:17 “The Lamb shall be their shepherd.”

ἐπίσκοπος. The verb is used of God “seeking out” His sheep in Ezekiel 34:11. In Acts 20:28 St Paul tells the elders at Miletus that the Holy Spirit has appointed them as ἐπίσκοποι to shepherd (ποιμαίνειν) the Church of God. In the LXX. ἐπίσκοπος is used of overseers, and so it came to be adopted in the N.T. as a title of those who had the oversight of the Church.