The word of God is given to us for our comfort and encouragement, but it also serves to shake us up when that is our greatest need. Our reading today is a shaker! The writer has been telling us that we have Jesus, who is the perfect one, given to us to deliver us from our sin. But now he tells us that if we choose to reject Jesus and stay in our sin, all that is left for us is judgment and sorrow! Wow. This is pretty serious stuff!
Now this is tricky, for Christians still have a sin nature and we still wrestle with sin even after we are saved. So when we read this passage we are worried that we are losing our salvation, but this is not the intent of this passage. The writer, writing mostly to Jewish people, is calling them to turn to Jesus for salvation and not return back to relying on obedience to the Law to save them. If they do this they are walking away from the only hope that they have of being saved.
But there is a truth here too for us. Jesus came to save us from our sin, not to free us up so we can sin. The Christian life must be one in which we are moving more and more away from the sin that God has saved us from. A willingness to sin all the more so that grace might abound might be an indication that our faith was never truly there in the first place.
So the writer of Hebrews shakes us up a little bit, calling us to avoid any deliberate sin as we live out our salvation in this life. For sin is never a small matter.