To understand who the “other sheep” from John 10:16 are, we must begin with the context of the verse and examine the whole passage. We know from many Bible passages that sheep are a symbol of true believers who follow Christ, their true Shepherd. His sheep hear His voice and follow Him. If He says that there are “other” sheep, then we must identify the original sheep that the “others” are different from.
Beginning in chapter 9 of John, we find Jesus discoursing at great length with the Pharisees after He healed a man who was born blind. He compares the man’s simple faith with the unbelief of the Pharisees and condemns them for their willful spiritual blindness. He begins by denouncing the false shepherds of Israel—the blind, self-appointed leaders who drew the people away from the true knowledge and kingdom of their Messiah (John 9:39-41). Then in chapter 10, He explains at great length the nature of true sheep, those who follow the Good Shepherd, sent and appointed by God. True sheep are those who listen to the voice of the Shepherd (v. 3) and follow Him (v. 4) and know Him (v. 14). He can only be speaking here of the true sheep of Israel because, up to that point, His ministry was confined to the sheep of Israel.
In verse 16, Jesus refers to the “other sheep,” and those can only be sheep that are outside of Israel, in other words, Gentiles. But the Gentiles who would follow Him are no less sheep than the true sheep of Israel. In fact, Jesus makes it clear that the Gentile sheep would also hear His voice and follow Him, and, eventually, there would be only one flock and one Shepherd. This is the mystery of the universal body of Christ, the church, which Paul refers to in Ephesians 3:6, “This mystery is that through the gospel the Gentiles are heirs together with Israel, members together of one body, and sharers together in the promise in Christ Jesus.” A mystery in Scripture is usually something not revealed previously, and this mystery—one universal church with both Jews and Gentiles brought together in one body in the Messiah—was so shocking to the Pharisees that they accused Jesus of being a demon-possessed lunatic (John 10:20-21).
Paul’s commission from Christ was to “preach to the Gentiles the unsearchable riches of Christ” (Ephesians 3:8) because the Gentiles, the “other sheep,” needed to be brought into the fold of the true Shepherd. Paul explains in Romans 11:16-36 the mystery of the church by using the imagery of a branch (the Gentiles) being grafted into the tree (Israel). Israel has been temporarily set aside until the “full number of the Gentiles has come in” (Romans 11:25). This is occurring now in the Church Age, but eventually both Jews and Gentiles will live in glorious harmony in the Millennial Kingdom and then in eternity when all true sheep will follow their Shepherd forever as one body.