If you subscribe to the Three Forms of Unity do you have to believe that Paul wrote the epistle to the Hebrews?
From Article 4:
Those of the New Testament are: the four Evangelists, viz., Matthew, Mark, Luke, and John; the Acts of the Apostles; the fourteen Epistles of the Apostle Paul, viz., one to the Romans, two to the Corinthians, one to the Galatians, one to the Ephesians, one to the Philippians, one to the Colossians, two to the Thessalonians, two to Timothy, one to Titus, one to Philemon, and one to the Hebrews; the seven Epistles of the other Apostles, viz., one of James, two of Peter, three of John, one of Jude; and the Revelation of the Apostle John.
From Article 4:
Those of the New Testament are: the four Evangelists, viz., Matthew, Mark, Luke, and John; the Acts of the Apostles; the fourteen Epistles of the Apostle Paul, viz., one to the Romans, two to the Corinthians, one to the Galatians, one to the Ephesians, one to the Philippians, one to the Colossians, two to the Thessalonians, two to Timothy, one to Titus, one to Philemon, and one to the Hebrews; the seven Epistles of the other Apostles, viz., one of James, two of Peter, three of John, one of Jude; and the Revelation of the Apostle John.