The Parable of the Good Shepherd is one of John's few parables. It emphasizes Christ's sovereignty: He is the great and benevolent Owner of His sheep.
Psalm 80 shows that the Shepherd of Israel sat between the Cherubim in the Holy of Holies, showing that Jesus Christ is the God who interacted with Israel.
Psalms 22, 23 and 24 form a trilogy, each part of of which is a Messianic prophecy that tells a part of the Gospel of God's Kingdom.
In Matthew 18, some disciples pondered who would be greatest in the Kingdom. However, ambition, arrogance, and pride will keep one from even being there.