"Many Christians who know John 3:16 are unaware of 1 John 3:16: "Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers."."
You are not the Body of Christ on your own. You need others to express that. Together, not separated, we are his Body.
A church family moves you out of self-centered isolation. The local church is the classroom for learning how to get along in God's family. It is a lab for practicing unselfish, sympathetic love.
As a participating member you learn to care about others and share the experiences of others: "If one part of the body suffers, all the other parts suffer with it. Or if one part of our body is honored, all the other parts share its honor." (1 Corinthians 12:26 NCV)
Only in regular contact with ordinary, imperfect believers can we learn real fellowship and experience the New Testament truth of being connected and dependent on each other. (Ephesians 4:16, Romans 12:4-5, Colossians 2:19, 1 Corinthians 12:25)
Biblical fellowship is being as committed to each other as we are to Jesus Christ. God expects us to give our lives for each other. Many Christians who know John 3:16 are unaware of 1 John 3:16: "Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers." (NIV)
This is the kind of sacrificial love God expects you to show other believers—a willingness to love them in the same way Jesus loves you.