In some of the most sobering words in Scripture, we are warned not to turn back from following Christ. We are shown that for us to do that, having come to understand something of the Gospel of God’s grace, is far more serious than it was to turn away from Him when less light was revealed (i.e. under the Old Covenant).
It is Christ Himself who speaks to us though this word, just as it was He who spoke to the people of Israel gathered at the foot of Mount Sinai. Most of Israel did not heed that warning and were denied what God had promised them because they lacked faith. How much less can we expect to escape God’s wrath and enter into heaven if we refuse to listen to Him now He is exalted at the right hand of God and has been appointed head over all things?
We see that this is a warning that has been given throughout this book. We are shown how important it is that we make our calling and election sure and press on to know Christ, rather than being amongst those who turn away and are consumed by the fire with which God will judge the world on the Last Day.