In 2 Peter chapter 3 we see Peter warning of the false teachings, but also encouraging Christians to look forward to the day of Christ which is to come. He encourages the people to live in holiness and godliness. He also tells them the way they can do this: by looking forward to the new heavens and earth which gives them the hope they need to pursue the holiness and godliness to which they are called. Peter finished the book with his final words of encouragement and a reminder that all of these things he has taught them and spoken of are for the glory of Christ alone. There is no other reason for these things.
In 1 John 1, John talks about the word of life. He reminds the people that Jesus, the word, has been there from the beginning and has now come and lived among them. They now have a way to claim eternal life through the sacrifice of Jesus! Then he shares the message that they had been taught that God is perfect and that nothing short of perfection will ever be enough. He encourages honesty and repentance and trust in Christ alone for the salvation. Anyone that thinks they are without fault John encourages them to repent and see their sin for what it is, so they can be forgiven.
1 John 2, John starts by proclaiming that Christ is our salvation. Christ intercedes for us. He is the propitiation for our sins. He goes to the Father on our behalf even when we sin. Praise the Lord for our savior! John then goes on to remind the people of the command to love your brother. He is telling them this to help them see how possible this is now because of the Holy Spirit and the hope the people now have for eternity. He then comes back to show them the importance of being set apart and loving the things of God and not the things of the world. John then give warns the people not to be distracted by the antichrists. He reminds them that any who deny who Christ is are not believers. All people who are saved believe in who Christ is. . Last but not least, abide in God. Let him be your focus and your hope.