The Church and her Members

What is the Church?
How does the Church come to exist?
Where is the Church?
What is the difference between the invisible Church and visible churches?
How do we determine that a church is a right teaching church?
How can a visible church rightly be called a church and still adhere to wrong teaching?
Are there members of the Church in churches that hold to wrong teaching?
What is our attitude and responsibility toward churches and church members who hold to wrong teachings?