[22] Having purified your souls by your obedience to the truth for a sincere brotherly love, love one another earnestly from a pure heart, [23] since you have been born again, not of perishable seed but of imperishable, through the living and abiding word of God; [24] for “All flesh is like grass and all its glory like the flower of grass. The grass withers, and the flower falls, [25] but the word of the Lord remains forever.” And this word is the good news that was preached to you. (1 Peter 1:22-25 ESV)The emphasis of much of 1 Peter chapter 1 is identity - specifically, our new identity as heirs of the heavenlies. We have already discussed how we have traded the death we were once due for the life that only Christ can offer. But does it end there? Do we just sit in that assurance that we now belong to life and will live it forever. No. Eternal life is coupled with eternal purpose.
We are born with a soul- It is within us and it is where all of our actions are birthed, and from childhood, those actions are tainted by the curse of Adam- our earthly inheritance of sin. But this natural bend and tendency towards sin is put to death along with Death, it's ultimate penalty, when we first hear of, and later respond to, the resurrection of Jesus Christ. This is the "good news" or the Gospel.
There is a moment in every Christian's life when the document is signed in a way... when the adoption becomes legal... when we respond to what Christ has done for us and his offer to make us his children (and simultaneously also his bride- we don't have an equivalent human relationship that fully encapsulates our relationship to the divine, so He uses many pictures.) It begins in us with a dawning of the truth, "Christ died for me- for all of us- to free us from sin and death." Then we respond by having faith and accepting his invitation for adoption, not by some magic prayer or mantra, but by sincere intention of the heart. But then what?
There is more to our response than just acknowledging we have been adopted- Does a kid adopted from a life on the street by a suburban family return to the sleep in the gutters? No! He acts in a way consistent with his new family- The focus here is not that his old ways were somehow wrong, but that it is not appropriate for him to continue to act like an orphan. He does not need to beg on the street corner for food when the family that has lovingly adopted him is home lovingly preparing a delicious celebration feast! And here Peter counsels that the way in which we act now that we are a part of Christ's family is to love. We are free from only ever knowing the soul's inward bend to sin, and indwelt now by the Holy Spirit, and surrounded by the assembly- the rest of our new family- who spur us on to good works, our lives reflect that of Christ. Sincerely and earnestly love from a pure heart is what the text says. Let your love flow from the deep wells within that have been transformed by the power and revelation of the truth of who Christ is and what he has done. If I may paraphrase the close of the first chapter of 1 Peter, "You've been made a son, now act like it!"