H. A. A. Kennedy 
St. Paul and the Mystery-Religions [PDF ebook] 

‘Ours is an age of new things. In no province is this more apparent than in that of New Testament interpretation. And no section of the New Testament continues to stimulate more revolutionary theories than the Pauline Epistles. It is true that discussions of authenticity have lost the importance assigned to them by scholars of the earlier time, like Baur, or by later critical investigators, like Van Manen. The emphasis has been shifted. The primary question at issue is the essential nature of St. Paul’s view of the Christian faith.’ – From Chapter One