2 Maccabees was written in Greek, probably in Alexandria, Egypt, c 124 BC. It presents a revised version of the historical events recounted in the first seven chapters of 1 Maccabees, adding material from the Pharisaic tradition, including prayer for the dead and a resurrection on Judgment Day.
Catholics and Orthodox consider the work to be canonical and part of the Bible. Protestants and Jews reject most of the doctrinal innovations present in the work. Some Protestants include 2 Maccabees as part of the Apocrypha, useful for reading in the church. Article VI of the Thirty-Nine Articles of the Church of England defines it as useful but not the basis of doctrine and not necessary for salvation.
The beginning of the book includes two letters sent by Jews in Jerusalem to Jews of the Diaspora in Egypt concerning the feast day set up to celebrate the purification of the temple (see Hanukkah) and the feast to celebrate the defeat of Nicanor. If the author of the book inserted these letters, the book would have to have been written after 124 BC, the date of the second letter. Some commentators hold that these letters were a later addition, while others consider them the basis for the work. Catholic scholars tend toward a dating in the last years of the second century BC, while the consensus among Jewish scholars place it in the second half of the first century BC.
It appears to be written for the benefit of the diaspora Jews in Egypt, primarily to inform them about the restoration of the temple and to encourage them to make the yearly pilgrimage to Jerusalem. It is written not from the point of view of a professional historian, but rather of a religious teacher, who draws his lessons out of history.
In general, the chronology of the book coheres with that of 1 Maccabees, and it has some historical value in supplementing 1 Maccabees, principally in providing a few apparently authentic historical documents. The author seems primarily interested in providing a theological interpretation of the events; in this book God's interventions direct the course of events, punishing the wicked and restoring the Temple to his people. It's possible that some events appear to be presented out of strict chronological order in order to make theological points. Some of the numbers cited for sizes of armies may also appear exaggerated, though not all of the manuscripts of this book agree.
The Greek style of the writer is very educated, and he seems well-informed about Greek customs. The action follows a very simple plan: after the death of Antiochus Epiphanes, the Feast of the Dedication of the Temple is instituted. The newly-dedicated Temple is threatened by Nicanor, and after his death, the festivities for the dedication are concluded.
Doctrinal issues that are raised in 2 Maccabees include:

In particular, the long descriptions of the martyrdoms of Eleazer 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 very 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.
2 Maccabees was condemned in Protestant circles. Many have suggested that this is the primary reason for its rejection—and following from that, the rejection of all the deuterocanonical books—by reformers such as Martin Luther, who said: "I am so great an enemy to the second book of the Maccabees, and to Esther, that I wish they had not come to us at all.