What does Paul mean by 'so also is Christ' in 1 Corinthians 12:12?
Paul means that just as a human body is one though it has many members, so Christ is one body composed of many members. He identifies that body as the Church, which is His body, with its head in heaven and believers as the members.
Les teaches that in 1 Corinthians 12:12 Paul is using the human body as an illustration: as the body is one and has many members, and all the members of that one body, being many, are one body, so also is Christ. The point is that the Church is His body. Earlier in the context Les distinguishes the called out assembly: it is the same Greek word Ecclesia, but in Paul's writings the church is the body of Christ, or the body which is the church, whose head is in heaven and whose members are believers. Les notes Peter in Acts makes no mention that Christ is the head of this called out assembly and that they are part of Him, stressing it is important to see what Scripture does not say as well as what it does say.
For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ.