Carnal Christians (1 Corinthians 3)

http://www.macarthurcommentaries.com ... And I, brethren, could not speak to you as to spiritual men, but as to men of flesh, as to babes in Christ. I gave you milk to drink, not solid food; for you were not yet able to receive it. Indeed, even now you are not yet able, for you are still fleshly. (1 Corinthians 3:1--3)
The cause of division in the Corinthian church was more than an external, worldly influence. It was also internal, fleshly. The Corinthians had succumbed to the pressures of the world, but they were also succumbing to the pressures and enticements of their own flesh.

Before Paul chastises them for their immature sinfulness, he reminds them again that he is speaking to them as brethren, as fellow believers. That is a term of recognition and of love. It reminded his brothers in Christ that they were still saved, that their sinning, terrible and inexcusable as it was, did not forfeit their salvation. He did not try to diminish the seriousness of their sins, but he did try to diminish or prevent any discouragement that his rebuke might otherwise have caused. He stood with them as a brother, not over them as a judge.
But Paul could not speak to the Corinthian believers as spiritual men. They had come through the door of faith but had gone no farther. Most of them had received Jesus Christ years earlier but were acting as if they had just been born again. They were still babes in Christ.
The New Testament uses the word spiritual in a number of ways. In a neutral sense it simply means the realm of spiritual things, in contrast to the realm of the physical. When applied to men, however, it is used of their relationship to God in one of two ways: positionally or practically. Unbelievers are totally unspiritual in both senses. They possess neither a new spirit nor the Holy Spirit. Their position is natural and their practice is natural. Believers, on the other hand, are totally spiritual in the positional sense, because they have been given a new inner being that loves God and is indwelt by His Holy Spirit. But practically, believers can also be unspiritual...

http://www.macarthurcommentaries.com