Luke 2:25-32 (ESV)
Now there was a man in Jerusalem, whose name was Simeon, and this man was righteous and devout, waiting for the consolation of Israel, and the Holy Spirit was upon him.  And it had been revealed to him by the Holy Spirit that he would not see death before he had seen the Lord's Christ.  And he came in the Spirit into the temple, and when the parents brought in the child Jesus, to do for him according to the custom of the Law,  he took him up in his arms and blessed God and said,
 "Lord, now you are letting your servant depart in peace,
according to your word;
 for my eyes have seen your salvation
 that you have prepared in the presence of all peoples,
 a light for revelation to the Gentiles,
and for glory to your people Israel."
The man finally gets to die, and he is happy for it! He happily embraces death because he has seen the Lord’s salvation. The Lord’s Salvation is Jesus Christ, this little child, barely a month and a half old. But Simeon has seen the salvation. He knows he is saved. He can go in peace.
We Lutheran’s sing his song after communion. As children perhaps we perk up when we hear this song because we know it’s almost over. As adults having heard this so often growing up, we sing for joy a little more understanding of Simeon. We sing with joy, knowing that we can meet life or death now, we have seen his salvation. Jesus has given us himself his body and his blood for the forgiveness of sins, for salvation. We are prepared as we need to be. We are at peace.