2 Peter 1:8-9 ⁸For these things which are for you and are increasing do not make you worthless or unfruitful in the knowledge of our Lord Jesus Christ. ⁹For for whom these things are lacking, he is blind as being nearsighted, receiving forgetfulness of the cleansing having from his former sins.

God’s will is our holiness (1 Peter 1:16; 1 Thessalonians 4:3), and this holiness is developed through growing and increasing in the virtues of verses 5-7. These qualities are God’s gift to us through his power for a fruitful, healthy, and peaceful life. The end result of all the virtues and character qualities of verses 5-7 is to know Jesus Christ better. Peter states this in a negative way, emphasizing the opposite of the highest worth and significant outcome of developing these virtues. The type of knowledge (epignōsin) referenced here was already mentioned in verse 3. It refers to a stronger form of knowing someone, especially in a personal and relational way. The way to experience the best way of life as God intended is to get to know Jesus through the life of faith and obedience. Knowing Christ was Paul’s prayer in Ephesians 3:14-21 and Philippians 3:7-11, where he called this knowledge the greatest pursuit of his life. Ineffectiveness comes from using the wrong source of strength and wisdom. If we find our values from our own thinking, humanism, culture, family, and many other things that point a different direction, we will end up ineffective and no new life.

Peter uses several images to highlight the need to increase in these virtues. Worthless gives the image of laziness and a “good for nothing” kind of person who accomplishes nothing of value. Unfruitful gives a similar sense of showing no results, something dry and useless. We should not be stagnated, passive Christians who do nothing to develop ourselves. Faith should grow and lead to love. Peter gives a clear path for that in these verses.

Being so nearsighted to the point of being blind implies people who cannot see beyond their own concerns and selfishness. They cannot see what God wants to do in their lives because they have closed themselves to God gift of transforming power through the Holy Spirit. They fail to go on to maturity and remain infants in the faith, and this shows up in how they live. At some point, unless faith is allowed to grow, love will not be empowered, and God’s purpose and design for us in this life will not be experienced.

Another problem from not growing in God’s grace is forgetfulness. The person forgets what God has already done. We must keep the memory of our salvation alive through consciously developing our faith through obedience to God’s will and purposes, particularly the knowledge of Jesus. The final image of cleansing (katharismou) is a significant biblical thought that refers to the removal of the stain of sin and effect of sin (Isaiah 1:18). Jesus’ own sacrificed blood is the removal agent of this stain. Forgetting this cleansing is equivalent to forgetting one’s salvation. A person can forget salvation by not growing in it. We live out our salvation by developing the virtues Peter lists.