This book by John Owen has an interesting subtitle. Read for yourself:
THE NATURE OF APOSTASY FROM THE IN AN EXPOSITION OF HEBREWS 6:4-6; WITH An Inquiry Into The Causes And Reasons Of The Decay Of The WITH REMEDIES AND MEANS OF PREVENTION. SEARCH THE SCRIPTURES — JOHN 5:39.
PROFESSION OF THE GOSPEL AND THE
PUNISHMENT OF APOSTATES DECLARED,
Power Of Religion In The World, Or The Present General
Defection From The Truth, Holiness, And Worship Of The Gospel;
Also, Of The Proneness Of Churches And Persons Of All Sorts
Unto Apostasy.
But that's just idle speculation ...
PS: A link to this book is in my Top Reads list to the right.