Peter himself warned other Christians saying, "Don't ever forget how you yourself were once cleansed from your sins" (2 Peter 1:9). He warns them there that if they do forget that, they will become blind and short- sighted. I don't ever want to be blind or short-sighted. I want to have a long-range vision - of heavenly values and eternal values - at all times.
Who are the short-sighted ones? Those who value earthly things - the pleasures of sin, material wealth and man's honour and approval. All such people are short-sighted. We need to feel sorry for such believers. If you see a man whose physical vision is so poor that he can't see anything more than 10 feet ahead of him, you don't get angry with him. You feel sorry for him. If you see a man who needs to keep a book 2 inches from his eyes in order to read it, you don't get angry with him. You feel sorry for him, don't you? If an eye- doctor asks a man wearing thick lenses whether he can read the "eye-chart" and the man replies that he can just about see the top letter but is not sure whether it is an "E or an "S", what does the doctor do? Does he get angry with him? No. He feels sorry for him.
And when we see believers who are so short-sighted as to live for money and the pleasure of sin and the approval of man, it's no use rebuking them. We must feel sorry for them, because they are so terribly shortsighted. They are going to have tons of regret when they stand before the Lord one day. There are lots and lots of believers like that. And do you know how they became blind? They forgot "their purification from their former sins" (2 Pet.1:9). They forgot the pit from which God pulled them out. They became proud of the fact that God blessed them subsequently.
I never want to forget the pit from which God pulled me out. I know that all my sins have been blotted out and that God does not remember even a single sin that I have ever committed. I stand before God today, just as if I had never sinned even once in the 60 years of my life - because I have "been justified by Christ's blood" (Rom.5:9). That's how God sees me. But I will never forget what I once was. God says to me "I will not remember your sins any more" (Heb.8:12). But I will always remember what I once was.
Now, I don't remember my past in such a way as to allow Satan to condemn me or depress me with the thought of my sins. No. Never. "There is no condemnation for those who are in Christ Jesus" (Rom.8:1). When the devil accuses me I tell him straight to his face that "the blood of Jesus has cleansed me from ALL my sins". I overcome Satan "by the blood of the Lamb"