Hi Leavingwt! "Abandon The Christian Faith" The christian faith is part of the religious realm. A realm in which it becomes very hard to find "Authenic Faith."
When one studies religious history and it's traditions one learns that all religions are susceptible to corruptions.
How then does one find "Authenic Faith?"
Many Reglions make "Absolute Truth Claims", demand absolute blind obedience, establish the "Ideal" time, the end justifies any means and history shows that they all have and had their "Holy Wars.'
People not only abandon the christian faith, they abandon their own cultural faith that they were born into.
You ask why, my response answers part of the question because there are many other reasons why.
Blueblades