Have you ever noticed a similar structure of many of Lutheran chorale tunes?
Usually they have 3 sections:
The first and the second are exact repetitions with different text followed by the remaining longer section - based on the thematic material, it looks like AAB form.
This is what they call the Bar form. Its origins rest in many German folk songs from the Middle Ages.
The two A sections in German are called Stollen and B - Abgesang.
The Stollen can have 2 or 3 phrases while the Abgesang is usually about twice as long.
Victoria yesterday asked my help for understanding the harmony and structure of the chorale prelude by Bach "Ich ruf zu Dir, Herr Jesu Christ", BWV 639 which comes from his Orgelbuchlein collection.
This was a good timing to introduce the concept of the Bar form to her.
So when you're playing any other chorale prelude which would be based on the Lutheran melody, try to identify those phrases and sections too.
Then you will be thinking strategically how composers did when they created these beautiful pieces.
Let me know if you need my help or feel stuck with anything in organ playing.