on what basis are the letters in the new testament ordered
New Testament The order of an early edition of the letters of Paul is based on the size of the letters: longest to shortest, though keeping 1 and 2 Corinthians and 1 and 2 Thessalonians together. The Pastoral epistles were apparently not part of the Corpus Paulinum in which this order originated and were later inserted after 2 Thessalonians and before Philemon. Hebrews was variously incorporated into the Corpus Paulinum either after 2 Thessalonians, after Philemon (i.e. at the very end), or after Romans.