On the Feast of St. Mark, our devotional reading comes from Concordia Commentary: Mark 1:1–8:26.

On the feast of St. Matthias, we read a brief biographical devotion about him taken from Treasury of Daily Prayer.

Our devotional reading for the feast of St. Thomas, Apostle is taken from Luther’s Works, Volume 69 (Sermons on the Gospel of St. John Chapters
17–20).

 The devotional reading for the feast of St. Simon and St. Jude, Apostles, comes from Meditations on the Gospels: According to His Word, where we consider the implications of today's Gospel from John 15.