Only the spiritual man can understand spiritual truths!

1 Corinthians 3:1-3 (a)

Brothers and sisters, I could not address you as people who live by the Spirit but as people who are still worldly—mere infants in Christ. 2I gave you milk, not solid food, for you were not yet ready for it. Indeed, you are still not ready. 3You are still worldly.

Paul is talking about the difference between the man who is spiritual (pneumatikos, Greek #4152), and who therefore can understand spiritual truths, and the man who is psuchikos (Greek #5591), whose interests and aims do not go beyond physical life and who is therefore unable to grasp spiritual truth. He now accuses the Corinthians of being still at the physical stage. But he uses two new words to describe them.

In 1 Corinthians 3:1 he calls them sarkinoi (Greek #4560). This word comes from sarx (Greek #4561) which means flesh and is so common in Paul. Now all Greek adjectives ending in -inos mean made of something or other. So Paul begins by saying that the Corinthians are made of flesh. That was not in itself a rebuke; a man just because he is a man is made of flesh, but he must not stay that way. The trouble was that the Corinthians were not only sarkinoi (Greek #4560) they were sarkikoi (Greek #4550), which means not only made of flesh but dominated by the flesh. To Paul the flesh is much more than merely a physical thing. It means human nature apart from God, that part of man both mental and physical which provides a bridgehead for sin. So the fault that Paul finds with the Corinthians is not that they are made of flesh--all men are--but that they have allowed this lower side of their nature to dominate all their outlook and all their actions.