1 Corinthians 3:2

3:2 I fed you milk, ¹  not solid food, for you were not yet ready. In fact, you are still not ready,

1 Corinthians 10:21

10:21 You cannot drink the cup of the Lord and the cup of demons. You cannot take part in the table of the Lord and the table of demons.

[3:2]  ¹ sn Milk refers figuratively to basic or elementary Christian teaching. Paul’s point was that the Corinthian believers he was writing to here were not mature enough to receive more advanced teaching. This was not a problem at the time, when they were recent converts, but the problem now is that they are still not ready.