Why does Paul call the Corinthians babes if they are saved?
Paul calls the Corinthians babes because, though they were saved, in Christ, and born again, they remained spiritually weak and fleshly minded. They were still controlled by the Old Adam rather than the Holy Spirit, so they needed milk, not solid food, having not grown in God's Word.
Les teaches that the word carnal here describes believers who have not really come out of the fleshly experience and are still under the control of the Old Adam rather than the Holy Spirit. He contrasts this with Romans 8, where carnal applies to the unsaved individual. Here, however, Paul is speaking of believers who are saved and in Christ, but still so weak spiritually that he speaks of them even as babes. Les explains that Paul fed them with milk, an analogy to a newborn who cannot take solid food. God expects growth from His children, but the Corinthians troubled Paul because they remained steeped in the flesh. They were believers, born again, and placed into the Body of Christ, yet still fleshly minded.