Since you have purified yourselves by obedience to the truth…you have been born again. Being born again is a [Christian] concept that describes a new life, specifically a life lived in a relationship with God. Jesus himself used this phrase in his conversation with Nicodemus (Jesus used the phrase being born from above cf. John 3:1ff). As popularly used today, being born again denotes a life that has been radically changed (for the better), a life that has been redeemed and currently grounded on the teachings of the Gospel. This is also the understanding that we get from our first reading today. Peter reminds his audience of whom they have come to be in an effort to call them to live up to their calling. He reminds them that in order to be true to their status as new creatures, they must always have in mind the means through which they were born again: obedience.
The sin of our first parents was that of disobedience. They ceased listening to God and went against what God had commanded them. They wanted their own way. They wanted “freedom,” to live independently of God. That sin of disobedience was undone by the obedience of Christ, who although he was like in God in everything, submitted to God his Father (cf. Phil 2:5ff). It is in this obedience of Christ that we are baptized (cf. Romans 6:3ff). In our baptism, we die to disobedience and assume new bodies, bodies that have become purified by the precious blood of Christ. Our new, born-again bodies become subject to the truth. Our new, born-again bodies become obedient to God. As Peter reminds us, we are obedient when we serve our brothers and sisters in sincere love. This is the mark of the redeemed. This is the mark of the born-again.