"Simeon . . . praised God, saying, 'Sovereign Lord, as you have promised. . . .'" — Luke 2:28-29
Traditionally Simeon is pictured as an aged man. While the Bible doesn't actually say he is old, it does imply he has been waiting a long time for God's promised Messiah, and he is clearly told that he will not die before seeing this child. So Simeon is probably quite old.
What is more important than Simeon's age is his song of praise. "Moved by the Spirit," he is in the temple when Mary and Joseph bring Jesus there to have him consecrated to the Lord. Then Simeon takes the child in his arms, praising God and declaring blessing and hope for all peoples.
First, Simeon claims the promises of God by faith. Imagine looking at this young child and trusting that he is indeed the Lord's Messiah. Simeon's song goes on to say that knowing Christ as Lord enables us to have peace with God. Finally, Simeon's song is filled with hope because he can see the all-encompassing work of God's great salvation in Christ for people of all nations.
Like Simeon, we too can look forward with hope. If you have truly trusted Jesus as your Savior, then you know that the best is yet to come. One day, like Simeon, you too will see Jesus face to face.
Do we need any more reason to sing?