Is 1 Corinthians 12 just elementary teaching for new Christians?
First Corinthians 12 is indeed described as rudimentary or elementary, but it is not merely that. The context says it is still all part of the Christian experience. Paul's discussion of the one body and its members remains relevant for believers, so it cannot be dismissed as only basic.
Les explains that in 1 Corinthians 12 Paul is back in the area of the rudiments, the elementaries, but nevertheless it is still all part of the Christian experience. The chapter begins at verse 12 with all the members of that one body. In the surrounding context, the believer's appetite is now on things spiritual because the Lord has given enough insight that these things last forever. The believer's position is in Christ, with spiritual blessings in the heavenlies. So even this elementary material remains part of the whole Christian life.
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.