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. For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins.
2 Peter 1:8-9
Peter makes it plain that the cultivation of these graces is not optional for the Christian. They are not only to be in us, they are to abound, and nothing less than this will ensure fruitfulness in Christian life. They are, so to speak, fruit-bearing graces, and we may recall solemnly the words of our Lord Himself in John 15 when He warns us that the branches of the vine that do not bear fruit will be taken away. Is this, we wonder, behind Peter's words in 9? At all events, to have 'no eye' for these essential lineaments of Christian character is to have misunderstood the real meaning of salvation and the true design of the gospel. According to Peter, and if we understand aright here, being purged from our old sins ought to involve the birth and growth of such graces in our lives. And in this he concurs with our Lord's own words in the Sermon on the Mount, 'By their fruits ye shall know them': If the fruit is not to be seen, it may well be questioned whether any real work of grace has taken place, and to this Peter next turns, in 10, to which we come in the next reading.