In 2016 a Pew Research Center survey received the following reasons Christians abandoned their faith:
Learning about evolution when I went away to college.
Religion is the opiate of the people.
Rational thought makes religion go out the window.
Lack of any sort of scientific or specific evidence of a Creator.
I just realized somewhere along the line that I didn’t really believe it.
I’m doing a lot more learning, studying and kind of making decisions myself rather than listening to someone else.
“And we know that all things work together for good to those who love God, to those who are the called according to His purpose. For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren. Moreover whom He predestined [to be conformed to the image of His Son], these He also called; whom He called, these He also justified; and whom He justified, these He also glorified.” Romans 8:28-30.
“Do not let your beauty be that outward adorning of arranging the hair, of wearing gold, or of putting on fine apparel, but let it be the hidden person of the heart, with the incorruptible ornament of a gentle and quiet spirit, which is very precious in the sight of God.” 1 Peter 3:3-4.