The Greek ekklesia, translated “church,” is used 118 times in the New Testament. It was a word already in usage in the Greek language  before the New Testament, and it meant, “assembly.” A church is an “assembly.” Another term given to the church, that is a metaphor, by the Apostle Paul is “body.” “Body” and “assembly” are synonyms. Very often in government an assembly is a body and a body is an assembly, used interchangeably. The church is the “body of Christ.” The body is one, and by that, it doesn’t mean there is only one body, but that each body is unified like a human body, all the parts working together. It’s not a body if it is not one, which is part of what “body” itself means. For the body to function as one, all the parts need to be working together. The parts are “members,” and this where the concept of church membership comes from. The goal of the body is to manifest Christ, Who is the Head of the Body. No one person can do that alone. He must function as a complement to all the members. The key is obedience, which is to function in obedience to the Word of God within the church. The church accomplishes the will of God in the world in this age in which we live. You are a part of it in the church.