In many ways, this is a letter of warning. Peter as spent his life preaching the Gospel of Jesus Christ and teaching Christians to hold to the truth and live by it. However, even in the first generation of the church, there were people who sought exploit the opportunities they saw in this new religion to get followers, wealth and power for themselves.
Peter reminded these Jewish Christians he wrote to that there were false prophets in the Old Testament days. Similarly, false preachers would try to deceive the church. They needed to be on guard, because these false preachers would be stirring orators who make big promises. They would have an appealing look, sound and message.
However, false teachers will be empty of substance. Their appeal is not to the heart seeking God, but to the flesh seeking to satisfy its lust, though they will try to disguise it. Watchful believers will recognize them by their sinful habits, covetousness, and lust.
The best guard against false teachers is to always remind ourselves of the truth. We are blessed to have the Word of God to test what we hear and no whether it is good or bad. We should remember that God is faithful, and if it seems that He is slow in coming, He is not. He promised to come again, to judge the world, to destroy what is evil, and to give His people eternal life with Him. We should be diligent in Christ-like character and good works, leaving little room for sin or the temptations presented by false preachers.
An interesting note is the bit of reconciliation Peter attempts to broker at the end of this letter. Paul was not a popular figure among the Jewish Christians. Peter validates Paul’s teaching and mission. It is a gracious thing for an old man to do after being one of the most prominent people in the church since its founding. He is more concerned with the truth, the continuation of faithful preaching, and the purity of the people than his position. If his reputation has value to him, it is in the opportunity it affords him to direct people to faithful, true teaching that will be around when he is gone.
Peter also wrote