What does the Bible say about recognizing a sheep?

In John 10, Jesus explains that His sheep hear His voice, know Him, and follow Him. This recognition is a divine act where the Holy Spirit opens the hearts of the elect to respond to the Gospel call. The Good Shepherd, having laid down His life for His sheep, has a personal and intimate knowledge of them, contrasting Himself with false shepherds who do not truly care for the flock. Therefore, recognizing a true sheep of Christ involves seeing their willingness to follow the Shepherd and respond to His voice in the Gospel.