In his sermon on 2 Peter 1:1-15, Dr. David Rose examines how to cultivate a growing faith that never becomes “obsolete.” He encourages us to evaluate our faith, to see if it lines up with the features described in this passage. Ultimately, faith in Christ’s righteousness provides the security we need to grow and to face even our deepest struggles. In Him, we have “everything pertaining to life and godliness, through the true knowledge of Him who called us by His own glory and excellence” (2 Peter 1:3).
Does Peter say that they have lost their cleansing from their past? No, he says they have forgotten it. So, imagine believers in the room who know Jesus, and remember that lifting of the weight of sin, all that shame that they were under has now been removed because Jesus hung on the cross and took their shame. All that weakness, because of the sin that was in their lives, has been replaced with the power of the Holy Spirit. All of that guilt, because of their sin, has been covered by the blood of Jesus, and they are innocent. And they forget that. Because they're not growing, Peter says all of that shame will begin to creep back in. Satan will start accusing them of what they used to be. All that guilt that they used to carry because they were trying to pay for their sins themselves, Satan will start putting that in the backpack on their shoulders once again. Peter says that if you are not growing, you will forget that you have been cleansed from your past sins.