This statement is the simplest definition for church that exists in the New Testament. The word church is that strange Greek word ekklesia. If we think of the ekklesia (or church) as Christ’s body, then Jesus has proclaimed himself head of that body.
If we think of the body of Christ as the church, then it is a living organism, rather than an organization. A living organism will be true to it’s DNA. We think of organizations as man-made, and organisms as God-made. Is it possible to have an organism without the organization? The answer is, yes. The ekklesia being a living organism draws it’s directives from it’s DNA, and the head of the DNA is Jesus.