Neglecting the elementary principles of God’s word, and failing to grow in the word makes a Christian vulnerable. Verses 4-8 are a crystal clear warning of the possibility of apostasy. This directly contradicts the preeminent doctrine held to by many, commonly called “once save always saved.”
Consider: The full context of Hebrews shows a letter written to faltering Christians, whose return to the Old Law with which they were familiar was a return to a system that could not save.
In our verses, we read of individuals who were enlightened by the gospel, and “tasted the good word of God and the powers of the age to come”, indicating they were Christians. The phrase “if they fall away” is not an impossible hypothetical (an absurd concept), but a description of what will happen should their faith weaken as warned.
What is referred to is the possibility of one who once was saved losing his salvation eternally. Verses 7 and 8 note the distinction: Bearing good fruit brings praise, bad fruit rejection, “whose end is to be burned.”
