Therefore, while the promise of entering his rest still stands, let us fear lest any of you should seem to have failed to reach it. -Heb 4:1
Geoffrey Wilson comments:
Such warnings against apostasy are misunderstood when they are thought to teach that true believers may fall away and be lost. For just as accidents are avoided by obeying the road signs which are put up for our safety, so we are preserved from the dangers of our pilgrimage by paying heed to those warnings which are annexed [attached] to the promise of salvation. This truth is further illustrated by Paul’s experience on the voyage to Rome. He had been divinely assured that all would be saved despite the loss of the ship (Acts 27:22-25), but that did not prevent him from warning the centurion that none could be saved if the sailors were allowed to desert the ship (Acts 27:31). … [A]ll who know the plague of their own hearts will never deem it safe to dispense with what God considers to be necessary for their spiritual safety.