All we like sheep have gone astray; We have turned, every one, to his own way; And the LORD has laid on Him the iniquity of us all.

Here the prophet Isaiah represents all the elect of God, Old and New Testament, whether Jews or Gentiles; whom he compares to "sheep", not for their good qualities, but for their foolishness and stupidity; and particularly for their being subject to go astray from the shepherd, and the fold, and from their good pastures, and who never return of themselves, until they are looked up, and brought back by the shepherd; so the people of God, in a state of nature, are like the silly sheep, they go astray from God, are alienated from the life of him, deviate from the rule of his word, err from the right way, and go into crooked paths, which lead to destruction; and never return of themselves, of their own will, and by their own power, until they are returned, by powerful and efficacious grace, unto the great Shepherd and Overseer [Guardian] of souls; see 1Peter 2:25 where the apostle has a manifest respect to this passage.

John Gill's Exposition of the Bible: Isaiah