Every person has a worldview or ideology that they live by. Many people have never conscientiously thought deeply about what they believe and why they believe it and this is what the devil (the enemy of our souls wants).
The Bible (God) explains in 1st Timothy 4:1 that in the last days some will depart from the faith some who may have said they were “Christians”). They will do this by devoting themselves to deceitful spirits and teachings of demons. So some will leave the church/ Christian fellowship and will be drawn away / tricked by supernatural spirits and demon teachings. Why?
Because #1 they did not love the truth and therefore take it seriously! The Bible is full of warning upon warning to “watch” what you believe, practice it and do not deceive yourself! Later in the same context in the same letter from Paul to Timothy in the Bible (1 Tim 4:16) Paul’s warns Timothy to, “Keep a close watch on yourself and on the teaching. Persist in this, for by so doing you will save both yourself and your hearers.”
Again he is urging believers to watch your lifestyle, to ensure that it is lining up with what you “say” you believe (James 2). For by doing this you want be deceived /tricked like the rest but rather you will be saved.
And last some will just simply love the world to much to continue with God! They love the stuff, their “friends”, their status, their jobs, etc… (1 John 2:15)