2Pe 1:5 For this very reason, make every effort to supplement your faith with virtue, and virtue with knowledge, 2Pe 1:6 and knowledge with self-control, and self-control with steadfastness, and steadfastness with godliness, 2Pe 1:7 and godliness with brotherly affection, and brotherly affection with love. 2Pe 1:8 For if these qualities are yours and are increasing, they keep you from being ineffective or unfruitful in the knowledge of our Lord Jesus Christ.2Pe 1:9 For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins.
In the above verse Peter is telling us that Christians who are not progressing in the Christian life, who are not making an effort to be conformed to the image of Christ by supplementing their lives with the qualities found in verses 5-7, have forgotten why they were saved. They are acting like they have not been cleansed from their sins by the death of Jesus Christ. This condition makes one ineffective and unfruitful as vs. 8 states.
The Bible teaches that Christians must be able to forget the sins committed before we were saved and move forward. Their guilt is covered by the blood of the cross so that we are free to enjoy and serve the Lord, Php 3:13 Brothers, I do not consider that I have made it my own. But one thing I do: forgetting what lies behind and straining forward to what lies ahead, Php 3:14 I press on toward the goal for the prize of the upward call of God in Christ Jesus. How could Paul who had murdered Christians ever get over that and serve the Lord? By understanding that those sins have been forgiven and are no longer being held against him.
So obviously at the same time we must never forget what the Lord did for us in saving us by grace. Had God not stepped into his creation and provided righteousness and atonement for us, we would be lost. This creates in us a humble heart of love and thankfulness that recognizes that all we are, have and will have is found in the cross work of Jesus.
The Bible also speaks of God forgetting and remembering things. We know that God never forgets anything so therefore he never has to remember anything because all knowledge is ever present in his mind. But this is worded in the Bible for us so that we can relate to how he thinks about us and cares for us. Let me give a couple of examples.
We can forget our sins because God has forgiven them in the cross and sometimes this is referred to as God forgetting our sins, Isa 43:25 "I, I am he who blots out your transgressions for my own sake, and I will not remember your sins. Jer_31:34 And no longer shall each one teach his neighbor and each his brother, saying, 'Know the LORD,' for they shall all know me, from the least of them to the greatest, declares the LORD. For I will forgive their iniquity, and I will remember their sin no more." This is quoted in Hebrews 10:17 so we know he is referring to the New Covenant. Mic 7:19 He will again have compassion on us; he will tread our iniquities underfoot. You will cast all our sins into the depths of the sea. In Micah the idea is that they are so far removed that they are no longer remembered by the Lord. The idea in these verses is that God no longer holds them against us so that for all practical purposes they have been forgotten.
But there is an interesting passage in Isaiah that connects the Lord’s forgetting with his remembering. The context of Isaiah 49 is looking forward to the Gospel Age when the Lord sets up his kingdom through Gospel preaching. But in Isaiah’s day things look rather bleak and they wondered if God would ever send the Messiah and set up the kingdom. We see this in vs. 14, But Zion said, "The LORD has forsaken me; my Lord has forgotten me." But Yahweh answers in an interesting way, Isa 49:15 "Can a woman forget her nursing child, that she should have no compassion on the son of her womb? Even these may forget, yet I will not forget you. Isa 49:16 Behold, I have engraved you on the palms of my hands; your walls are continually before me.
How is it that we can be assured that God will never forget his children, that he will always love us and keep us with him forever? Because he has something to look at for all eternity that will not allow him to forget. Jesus will always bear the marks of the cross in his hands as a reminder to God and to us that our sins have been paid for and can no longer separate us from the love of God! Of course, the Father doesn’t need a reminder but he is illustrating how there is no way he will forget the sacrifice his Son made for us.
Rom 8:34 Who is to condemn? Christ Jesus is the one who died—more than that, who was raised—who is at the right hand of God, who indeed is interceding for us. Rev 5:6 And between the throne and the four living creatures and among the elders I saw a Lamb standing, as though it had been slain, with seven horns and with seven eyes, which are the seven spirits of God sent out into all the earth.
Jesus will always bear the marks of the cross as a reminder to us and to the Father of his perfect sacrifice. They have been engraved in his hands as an eternal reminder. What a God we serve!