6.
Books which formed the original canon of the New Testament and which have always been accepted by Christians.
Matthew, Mark, Luke, John, Acts, Romans, 1 Corinthians, 2 Corinthians, Galatians, Ephesians, Philippians, Colossians, 1 Thessalonians, 2 Thessalonians, 1 Timothy, 2 Timothy, Titus, Philemon, 1 John.