Doctrinal issues that are raised in 2 Maccabees include:
Prayer for the dead and sacrificial offerings, both to free the dead from sin
Merits of the martyrs
Intercession of the saints (15:11–17) (at least as seen from a Christian viewpoint); the New American Bible comments on verse 14 “Jeremiah’s prayer in heaven has been taken in the Roman Catholic tradition as a biblical witness to the intercession of the saints”
Resurrection of the dead
Specific mention of creation ex nihilo (II Maccabees 7:28)
In particular, the long descriptions of the martyrdoms of Eleazar and of a mother with her seven sons (2 Macc 6:18–7:42) caught the imagination of medieval Christians. Several churches are dedicated to the “Maccabeean martyrs”, and they are among the few pre-Christian figures to appear on the Catholic calendar of saints’ days (that number is considerably higher in the Eastern Orthodox churches’ calendars, where they also appear). The book is considered the first model of the medieval stories of the martyrs.
Catholic apologist Jimmy Akin examines Hebrews 11:35 (“Some were tortured, refusing to accept release, that they might rise again to a better life”) and notes that this hope of eternal life after torture is not found anywhere in the Protocanonicals of the Old Testament, but is found in 2 Maccabees 7.
Catholics and Orthodox regard 2 Maccabees as canonical. Jews and Protestants do not. 1 and 2 Maccabees appear in manuscripts of the Septuagint along with (in some copies) 3 and 4 Maccabees and Psalm 151. The Codex Vaticanus lacks 1 and 2 Maccabees (but includes 1 Esdras) which Codex Sinaiticus includes along with 4 Maccabees (but omits Baruch), which evidences a lack of uniformity in the lists of books in early manuscripts of the Septuagint. Neither 1st nor 2nd Maccabees were found among the Dead Sea Scrolls.
