And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you; And account that the long-suffering of our Lord - Conclude that God's long-suffering with the world is a proof that he designs men to be saved; even as our beloved brother Paul. "This epistle being written to those to whom the first epistle was sent, the persons to whom the Apostle Paul wrote concerning the long-suffering of God were the Jewish and Gentile Christians in Pontus, Galatia, Cappadocia, Asia, and Bithynia. Accordingly, we know he wrote to the Ephesians, (Ephesians 2:3-5), to the Colossians, (Colossians 1:21), and to Timothy, (1 Timothy 2:3, 1 Timothy 2:4), things which imply that God's bearing with sinners is intended for their salvation. The persons to whom Peter's epistles were sent were, for the most part, Paul's converts." - Macknight.
According to the wisdom given unto him - That is, according to the measure of the Divine inspiration, by which he was qualified for the Divine work, and by which he was so capable of entering into the deep things of God. It is worthy of remark that Paul's epistles are ranked among the Scriptures; a term applied to those writings which are divinely inspired, and to those only.