God places great emphasis on the local church. They for sure were not perfect but God wants all of the body of Christ to be functioning. How terrible for a hand or a foot not to be working in the body of Christ. Think of what they are missing by not being use of God. Think of the loss of rewards at the Judgment Seat of Christ.
Every person needs the feeling of being included.
We all need to feel a vital part and not an outsider of our family, our neighborhood, our city, our country, our jobs and our church if we are going to get anything out of it or put anything into it. This is especially true of our relationship to a church. As long as you are not a member you will have an incomplete feeling, a feeling of being an outsider, of not belonging. It is not your church. You feel no responsibility nor will you take nay responsibility for what happens there.