The main entry's account of the canon's formation states the broad process but not which books were genuinely disputed, and the list of contested texts, the antilegomena, "spoken against," is itself informative about what later Christian communities found doctrinally or historically uncertain.
Origen and Eusebius specifically classed Hebrews (disputed partly over authorship, since its style differs markedly from Paul's undisputed letters), James, 2 Peter, 2 and 3 John, Jude, and Revelation as antilegomena, books read and valued in many churches but not universally accepted as apostolic when Eusebius wrote in the early fourth century, in contrast to the homologoumena, the universally acknowledged books including the four Gospels, Acts, and Paul's major letters. Revelation's status was particularly contested in the Greek-speaking East, where several influential figures and even some later Byzantine lectionary traditions downplayed it, while James and Jude faced questions partly from their obscure authorship and late circulation.
The dispute did not end with the fourth-century lists: Martin Luther, translating the New Testament in the 1520s, relegated Hebrews, James, Jude and Revelation to a separate section at the end without page numbers continuous with the rest, reflecting his own reservations, most famously calling James "an epistle of straw" for its apparent emphasis on works over faith alone, though he did not formally remove these books from the canon, and Lutheran churches subsequently retained all of them as scripture. The episode shows that even after a canon is formally closed, individual books can remain sites of live theological unease, precisely the interpretive afterlife the main entry predicts closed canons generate.