Love your family. That's one of the primary messages of 1st John. Do you love God? Then you will love His children. Are you born of God? Then you will love the other's who are born of God.
How do we know if we're loving our brothers and sisters in the church? The haunting answer from John is this: When we obey God's commandments. The one who honestly considers this will despair. Love of God and love of Church are inseparable and have we loved the Church? Yes, in a weak way. Yes, in a selfish way. Yes, in an incomplete way. This will always call us to call out to God for mercy as we strive to love each other even in our brokenness.