Peter is finishing the letter. After multiple exhortations on the proper behavior, the mutual submission that we are all under, he has commanded them be sober and vigilant. This is because we are part of a spiritual battle, a battle that is against satan. Satan is roaring, seeking to intimidate us, threatening us, looking for those that he can devour. This isn't to say that he can take us out of the Father's hand, but that those who come close but don't fully close / finish with God will have that which they do have taken away. (Matt. 13) Join us as Peter closes the letter the same way that he opened it, focusing on God and His work. It is here that we find our comfort and peace in a world that is lost in sin.