LL of us who own a mansion in heaven (John 14:2) have the very same religion. We may attend churches with different denominational names on the sign out front, but money that is legal tender is legitimate whether it's a 1, 5, 20, 50 or 100. There is only one church, one Lord, one faith, & one experience of regeneration (Ephesians 4:4-6). There is one Bible, one gospel, & one body of truth that has been revealed to us. There are, then, only two kinds of people: those in on this, & those not. So, Peter wrote this letter to an esoteric audience. He only addresses those of us who are born again; who are the followers of Christ; who possess the same precious faith that was preached by Christ & His apostles (vs. 1). We are the ones to whom (through the person of His Son) God has given all good things (vs. 3). He has made marvelous promises to us. We are "partakers of the divine nature" - Hallelujah! We have "escaped the corruption that is in the world" (vs. 4). We are truly blessed beyond measure.
But, to whom much is given much is required (Luke 12:48). Peter reminds us of our privileged position in Christ (vs. 1-4), that's for sure. However, he moves on into the deeper waters of obligation & spiritual growth. So, we all possess the same faith. It is our duty, though, to build something eternal on that good foundation (1st Cor. 3:11-15). We are called to move ever onward & upward to higher plains of virtue, knowledge, temperance, patience, godliness, kindness & love (1st Peter 1:5-7). Life & abundant life: that's the recipe, right (vs. 8)? Life alone is not our destination, even though it is eternal (1st Cor. 3:15). God saved us for some purpose (Eph. 2:10). We must not waste God's grace or space. Our lives are supposed to be invested. Peter exhorts us as believers to confirm our salvation through a continual demonstration of godliness (vs. 9-11).