In their zeal to eliminate good works as a requirement for salvation, some have gone to the extreme of arguing that good works are not even a valid evidence of salvation. They teach that a person may be genuinely saved yet never manifest the fruit of salvation—a changed life.
A few have even taken the absurd position that a born-again person may ultimately turn away from Christ into unbelief, deny God, and become an atheist—yet still possess eternal life. One writer invented a term for such people: "unbelieving believers"!
Scripture is clear that a saved person can never be lost. It is equally clear that a genuine Christian will never fall back into total unbelief. That kind of apostasy proves an individual was never really born again (1 John 2:19).
Furthermore, if a person is genuinely saved, his life will change for the better (2 Corinthians 5:17). He is saved "for good works" (Ephesians 2:10), and there is no way he can fail to bring forth at least some of the fruit that characterizes the redeemed (cf. Matthew 7:17). His desires are transformed; he begins to hate sin and love righteousness. He will not be sinless, but the pattern of his life will be decreasing sin and increasing righteousness.