For whoever lacks these qualities is so nearsighted that he is blind, having forgotten that he was cleansed from his former sins.
9. But he that lacketh these things. He now expresses more clearly that they who profess a naked faith are wholly without any true knowledge. He then says that they go astray like the blind in darkness, because they do not see the right way which is shewn to us by the light of the gospel.
In these words the apostle comes to the chief thing intended in this epistle - to excite and engage them to advance in grace and holiness, they having already obtained precious faith, and been made partakers of the divine nature. This is a very good beginning, but it is not to be rested in, as if we were already perfect.
Commenting on 2 Peter 1:5-11
But he that lacketh these things,.... Or in, and with whom, they are not; that is, these virtues, as the Arabic version reads, as faith, virtue, knowledge, temperance, patience, godliness, brotherly kindness, and charity; where the principles of those things are not, and they are not exercised and performed, such an one is blind: let him boast ever so much of his light and knowledge...