Since you have in obedience to the truth purified your souls for a sincere love of the brethren, fervently love one another from the heart, for you have been born again not of seed which is perishable but imperishable, that is, through the living and enduring word of God. (1 Peter 1:22-23)That's interesting, isn't it? The command here is not to fervently love your wife or fervently love your neighbor. The command here is to fervently love the brethren. It is to be a sincere love, a love from the heart. In fact, it says that this is a primary function of believers. Peter says, "Since you have in obedience to the truth purified your souls for a sincere love of the brethren, fervently love one another from the heart ..." That "since" and "for" indicate reasons. On the basis of A, do B. What is A? You have in obedience to the truth purified your souls. Purified your souls for what? For a sincere love of the brethren. What is B? On the basis of A, fervently love one another from the heart. Cause and effect.
Christianity, especially in America, has succumbed to the "me" kind of thinking. You'll find all sorts of worship songs about "me" and what He has done for "me" and how much He loves "me". We are fond of saying, "He died for me." This isn't all false, but it becomes problematic when it makes "me" the center of this relationship. So Christianity has largely moved from "us" and "we" to "me" and in that move you'll hear a lot of "I don't need the church to worship Christ." You'll hear a lot of "I feel closer to God in a forest than in a church." And this is missing the point. Peter is saying that the reason we turned our lives over to Christ ("In obedience to the truth purified your souls") is to have a sincere love of the brethren. That ought to cause you to love them fervently. And you can't do that alone in the woods. It's not the point.
We were called to love one another -- believers. We were told it was the hallmark of believers (John 13:35). And still we buy that lie that the key relationship is between me and Christ and we don't need anyone else in this. The key relationship is with Christ, but that relationship demands that we love one another and we do so fervently from the heart. Try to do that without close relationships and constant interactions and involvement with other believers. That wouldn't make any sense.