Psalms 22—24 are a group of psalms revealing Christ from His crucifixion to His kingship in the coming age. In Psalm 22 we see Christ's death, His resurrection, and His many brothers produced in His resurrection to form His church. Psalm 23 is concerning Christ as the Shepherd. This Shepherd today is in His resurrection. Psalm 24 is concerning Christ as the coming King in God's kingdom. Thus, in these three psalms, we have Christ crucified, Christ resurrected, Christ producing the church, Christ being the Shepherd and shepherding His flock, the church, and Christ coming back to be the King.
Psalm 23:1 says, "Jehovah is my Shepherd." Christ is our Shepherd and we are His flock. The church in the Bible is called a flock. In John 10 the Lord said that He was the good Shepherd who would collect the sheep from Israel and from the Gentiles to form them into one flock (vv. 14-16), which is the church (1 Pet. 5:2; Acts 20:28).
Jehovah, of course, is the divine God, and we are mere humans. How can God, the divine One, approach us human beings to be our Shepherd? If God would come to us in a direct way, that might frighten us to the uttermost. The Bible tells us that this happened when God appeared to various people (Rev. 1:17; Gen. 17:3; Dan. 8:17; Matt. 17:6). The Bible also tells us that no one can see God (1 Tim. 6:16; John 1:18; Exo. 33:20). How can the divine Triune God be so close to us, just as a shepherd is to his flock? Furthermore, how can we sinners, the fallen people, be the flock of the divine Shepherd? According to our fallen nature we are snakes, vipers (Matt. 23:33), and "scorpions."
Psalm 23 implies that this Shepherd is the One who became a man, who died for us to redeem us and wash away our sins, and who entered into resurrection to become a life-giving Spirit (1 Cor. 15:45b) to regenerate us. As such a One, He can change our nature. Since He has taken these three steps—1) incarnation; 2) crucifixion for redemption; and 3) resurrection for regenerating—He is altogether qualified, equipped, and suitable to be our Shepherd. He is not only God but also a man. He is not only divine but also human. He died for our sins, He was resurrected, and in His resurrection He became a life-giving Spirit.
The Lord Jesus today is the Spirit (2 Cor. 3:17). As the life-giving Spirit, He is our Shepherd inwardly. He is not only with us but also within us. We were snakes and scorpions, but we have been redeemed, we have been washed in His blood, and we have been resurrected (Eph. 2:6) and regenerated. As those who have been redeemed, washed, resurrected, and regenerated, we are the sheep of God's flock, the church. By Jehovah, the Triune God, being incarnated, crucified, and resurrected to become the life-giving Spirit, He is qualified to be our Shepherd. By His redeeming, washing, resurrecting, and regenerating us, we are qualified to be His flock. He is qualified to be our Shepherd, and we are also qualified to be His flock. Psalm 23 is altogether a psalm on Christ as the Shepherd in His resurrection.