A Hymn for the feast of St. Matthias

[The Conductor]

Ok, so I know that calendar-wise, this couldn't be at a weirder time, but I wrote a poem for the Feast of St. Matthias today, and I was wondering a few things:
1) What do you think?
2) Does it jive with Lutheran theology? Could it be improved in that area?
3) Could the wording or style be improved?
4) Does anyone know a good tune to put this to?
5) Does anyone even celebrate the feast of St. Matthias?

The poem is based on the Epistle and Gospel readings for the feast of St. Matthias, and hinges on the fact that Barsabbas means 'son of Sabbath' and Matthias means 'granted of God'. The readings are Acts 1:15-26 and Matt. 11:25-30.

Disciples gathered all in prayer
Desired the Lord to answer there
To choose by lot a man to send
Begun with grace, with what to end?
To take up the old man’s office?

The old man, betrayer of the Lord
That Saul who fell upon his sword
May all his camp be desolate,
And let there be no one to dwell in it-
Another will take his office.

Now dead the old, behold the new.
But which to choose between the two?
The son of Sabbaths? Granted of God?
Just one with whom the Saviour trod
was fit to be His Apostle.

Begun by grace, by grace will end.
Matthias was counted the Saviour’s friend.
No heavy burden on them was laid-
The price for every man was paid!
With joy they worshiped together!