2 Pet 1:7 And to godliness brotherly kindness; and to brotherly kindness charity. KJV
ADD CHARITY TO BROTHERLY KINDNESS
Another word for charity is love. Apostle Peter is telling us to add love to our faith in Jesus. Here, he was not talking about erotic love neither is he talking about the love that exist between friends. The type of love Apostle Peter is telling us to add is a sacrificial love. Love without selfishness. This is what is commonly known as "Agape" love. The perfect example we have for this is God, John 3:16, Romans5:8.
Our love must be two- dimensional, love towards God and love towards men. How do we love God? What is the proof of our love towards God? Is it when we sing about our love to God and shed tears about it? The answer to this question can be found in scriptures. "If ye love me, keep my commandments"(John14:15). I don't think you need further explanation on that. Loving God is not a feeling that you feel when you feel you are feeling something. The proof of love towards God is obedience. You may sing about loving God and not love God with all your heart.
1Cor13:4-7 describes what love is towards our fellow humans. Take your time to study it. You cannot love fellow humans if you don't love God. Sacrifice and selflessness is the hallmark of love towards people. "Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren" (1John3:16). In the flesh, we cannot achieve this. We need to stay hooked to God who is love himself.
Father, perfect me in love in Jesus name.