The universal witness of the New Testament is that apostasy if persisted in not only damns but shows that salvation was never real in the first place. The New Testament reveals how close one may come to the kingdom – tasting, touching, perceiving, understanding. And it also shows that to come this far and reject the truth is unforgivable.
Yes, apostasy happens. Sometimes the catalyst is flagrant sin. The pain of conviction and repentance is refused, and the only alternative to it is wholesale rejection of Christ. But sometimes the catalyst is a thorn growing quietly in the heart, an indifference to the way of the Cross, a drifting that is not reversed by the knowledge of biblical warnings.
None sink so far into hell as those that come nearest heaven, because they fall from the greatest height.
Thousands today change what they believe to accommodate their moral behavior. On the other hand, thousands more take up false doctrine, then apostatize in their actions.
Apostasy isn’t an unintentional departure or personal struggle with doubt. It is deliberately abandoning the truth for erroneous teaching. “The faith” refers specifically to the body of Christian doctrine, not the act of believing. Some will depart from “the faith which was once delivered unto the saints” (Jude 3). People who understand and outwardly affirm Christian doctrine but don’t have a heart for God are prime candidates for being seduced by demons away from the faith.
No one sets out to become an apostate – it’s never the result of one abrupt, drastic turn away from the Lord. Instead, apostasy is most often the product of a pattern of sinful compromises that harden and gradually steer a professing believer away from the truth.
Religion which is begun in hypocrisy will certainly end in apostasy (William Spurstowe).
Remember that if you are a child of God, you will never be happy in sin. You are spoiled for the world, the flesh, and the devil. When you were regenerated there was put into you a vital principle, which can never be content to dwell in the dead world. You will have to come back, if indeed you belong to the family.
The essence of apostasy is changing sides from that of the crucified to that of the crucifier.