There is a twofold message in 2nd Peter.

(1) Develop believers knowledge of the Truth so as to be able to defend the Truth against false teachers. Their false teaching being deceptive lies and denials of Truth and also immoral behaviour.
(2) General exposure of false teachers who lead astray the weak sheep.

Peter fulfils the commission of the Lord Jesus Christ given to him in John 21:15-17. “Feed my lambs, feed my sheep.” Peter is an under-shepherd caring for the flock for the Chief Shepherd. READ 1st. Peter 5:2-4. Peter lives out what he tells others to do.

Second Peter, like Jude, is the most graphic and penetrating exposure of false teachers. 2 Peter 2:1…”they shall bring in their destructive (AV says damnable) heresies, denying the Lord who bought them (explain bought) and bring upon themselves swift destruction”.

2 Peter and 2 Timothy have much in common, Peter and Paul knew their martyrdom was near and wanted to write vital truths with warnings of Apostasy getting worse towards the end of the professing Church Age. Rev.2:6.-Professing priesthood hold power over the true believers.
NB. At the end of the N.T. 2 Timothy, 2 Peter and 1st John with Jude deal with Apostasy and false teachers already infiltrating the Church to deceive and lead astray the flock, like tares among the wheat with their poison. The only antidote is our Bible School emphasis –“Know the Word – know the Lord”. See 2 Peter 3:18.

There is no note of discouragement or dejection but rather positive confidence and challenge to believers to press on and upward. Read 2 Timothy 4:1-8, 1st. Peter 5:6-11 & 2nd. Peter 3:10-18.

God keeps His promised Word – hold fast, keep strong, stand firm. THIS IS THE STRONG PLEA FROM SECOND PETER.

Grow in Grace and guard against enemy intrusion and infiltration. Defend the faith as a good soldier of Jesus Christ.. Jude 3 says, “contend earnestly for the Faith”. Believers have a sacred duty to guard holy treasure – the Word of God, the Truth and Treasure. See 1st Peter 5:12(b).

False teachers deny the deity of Christ and the means of Redemption (Blood), twist the Scriptures, bringing true faith into disrepute, attempting to undermine it (did God say?) and mock the Second Coming of Christ.
For the true Believers the over-riding challenge to counter false teaching is to “rightly interpret(divide) the Word of God. 2nd Peter 1:19-21. As Paul is inspired to write, “Rightly divide the Word of God”,( i.e. cut it straight as a stone is cut to shape and size, exalt the work on the stone), 2 Timothy 2:15. “Hold fast the pattern of sound words”, 2 Timothy 1:13.

Ch.1:1-11. Know the principles of your salvation – safe and secure.
Ch.1:12-21. Know the Scriptures – making you wise in your salvation (2 Tim.3:15).
Ch.2:1-22. Know your adversaries – the perils that are planted (tares).
Ch.3:1-18. Know your prophecy. Fulfilment of God’s planned future – know the precepts of prophecy.