"I am the Good Shepherd, and I know My own and My own know Me... I lay down My life for the sheep. I have other sheep, which are not of this fold; I must bring them also, and they will hear My voice; and they will become one flock with one shepherd" (John 10:14-17).
Have you ever read through these verses and considered the fact that Jesus says His sheep WILL hear His voice? The significance of this can be overlooked. Ponder that my friend. Whoever the sheep are; wherever the sheep are... they WILL hear His voice. Does that leave any possibility for one of the sheep of Christ to possibly fail to hear His voice? Have you ever pondered that before? The words of Christ inform us that God knows intimately who His sheep are: "I know My own and My own know Me" (10:14). Some of these He speaks of are not yet regenerated. The Spirit enlightens us to the reality of God's foreknowledge of His elect: "For those whom He foreknew, He also predestined", and also we are told that "these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified" (Romans 8:29-30). Thus we are taught that the sheep of Christ are foreknown intimately by their Father. We are also taught that the sheep of Christ, being foreknown by God, are predestined, called, justified, and finally glorified. This is an unbreakable chain that we read of. In fact, because God is outside of time, eternal, and omniscient, this redemption of His sheep is spoken of in the past tense: "He predestined...He called...He justified...He also glorified"!
Jesus already knows who all of His sheep are. The sheep of Christ were given to Him by the Father before Creation: "I do not pray on behalf of the world, but on behalf of those whom You have given Me", and again, Jesus praying to His Father says: "You gave Him authority over all flesh, that to all whom You have given Him, He may give them eternal life" (John 17:9, 3). The "all whom You have given Him" that Christ speaks of are the elect of God, the sheep. These people were given to Christ in eternity past.
The salvation of Christ's sheep is certain: "I MUST bring them also" (Christ said this of His Gentile sheep, who He would join together as "one flock" with His Jewish sheep). "All that the Father gives Me will come to Me" (John 6:37). Every one of them will come. And who can come but those who are born from above? "born, not of human blood, nor of the will of the flesh, nor of the will of man, but of God" (John 1:13).
This beloved is the why the Great Commission exists. This is HOW we can fulfill the Great Commission. This is why we can fulfill the Great Commission with absolute confidence in the sovereignty of saving grace. Christ's sheep will hear His voice. Paul said to the Thessalonians: "We give thanks to God for you...knowing brethren, beloved of God, His choice of you" (1 Thessalonians 1:2, 4). So how do Christ's sheep hear His voice? Paul continues: "for our Gospel did not come to you in word only, but also in power and in the Holy Spirit, and with full conviction" (1:5). The Holy Spirit applies the redemption of Christ to the elect of God through the ministry of Gospel preaching. Paul says his Gospel didn't come "in word only". It's the Holy Spirit who produces the supernatural power of regeneration in a person, as He convicts them of their sin and draws them to Christ. This is the new birth (John 1:13, John 3:3). The Gospel which comes "in word only" isn't sufficient to convert a person. And this is the great hope in Gospel preaching. This is why we need not worry ourselves over our human weaknesses. God saves! And He has chosen to do so through the preaching of the Gospel of Christ. James also testifies that: "In the exercise of His will HE brought us forth BY the word of truth, so that we would be a kind of first fruits among His creatures" (James 1:18). Notice it was His will that brought us forth, and that He did so by, or through, the word of truth.
So who are the sheep of Christ? The Scriptures don't inform us who they are, but they do instruct us in how we can recognize a sheep who has been born-again already. Though I won't go into detail on this point, we are taught that Christ's sheep, in being regenerated (born from above), are given a new nature (2 Corinthians 5:17). The disposition of their heart is changed. Christ has become their treasure. They're growing in their hatred for what God hates. 1 John 2:3-6 informs us that the practice of their life now is one of obedience and righteousness, rather than sin. They're no longer slaves to sin (John 8:34), but have been set free to serve Christ (John 8:36). However imperfect the sheep's love for God and hatred for sin may be, they characterize who they are in Christ (Romans 8:1-2, 4); and they're two characteristics of their lives that God will grow (Philippians 1:6, 2:13, Hebrews 12:6-10).
You who have already heard His voice and been saved, God has sheep out in the world who have yet to hear His voice. May we be burdened and inspired to reach them with the Gospel for His glory. Let us awaken our cold hearts and start getting after the Great Commission with Holy Spirit-wrought zeal! His sheep will hear His voice; and blessed are they who partake of the fruit of the salvation of souls. What further motivation do we need? For His glory friends! That the Lamb may receive the rewards of His sufferings!
If your chief motivation in missional living is that people's lives be improved, I urge you to forsake your humanistic tendencies. The Gospel is not all about man's life being improved. The Gospel is not all about man. The Gospel is about God's justice being vindicated! God has been wronged. God has been sinned against! And God's wrath abides upon sinners. Either they repent or they perish. Either they be converted or they burn in the lake of fire forever. God will draw His own to repentance. Let us be faithful to preach the Gospel of Jesus Christ for God's glory, and not chiefly for man's sake. Let us be careful to not get discouraged when the masses don't seem to respond well. The sheep of Christ are but a remnant. Go out covered in tears from prayer, with the authority of God, in the power of the Holy Spirit, preaching the uncompromised message of repentance and faith, and with the confidence that Christ's sheep WILL hear His voice... and all this to the glory, and honor, and praise of the Lamb.