“For by a single offering he has perfected for all time those who are being sanctified.” Hebrews 10:14 (ESV)
In his book Fifty Reasons Why Jesus Came to Die, John Piper lists fifty reasons why Jesus came to die. Of course, Jesus’ ultimate motivation was to follow the will of the Father, but this book gives details as to what glorifying God entails. Piper’s fifteenth reason why Jesus came to die is “to make us holy, blameless, and perfect.” Here’s what Piper says about Hebrews 10:14:
One of the greatest sources of joyu and endurance for the Christian is knowing that in the imperfection of our progress we have already been perfect-and that this is owing to the suffering and death of Christ. “For by a single offering [namely, himself!] he has perfected for all time those who are being sanctified” (Hebrews 10:14). This is amazing! In the same sentence he says we are “being sanctified” and we are already “perfected.”
Being sanctified means we are imperfect being made holy – a work in progress! It is those who are being sanctified who are already perfect. Piper adds, “The joyful encouragement here is that the evidence of our perfection before God is not our experienced perfection, but our experienced progress. The good news is that being on the way is proof that we have already arrived.”