1 Corinthians 3:1-3

1 And I, brethren, could not speak to you as to spiritual people but as to carnal, as to babes in Christ. 2 I fed you with milk and not with solid food; for until now you were not able to receive it, and even now you are still not able; 3 for you are still carnal. For where there are envy, strife, and divisions among you, are you not carnal and behaving like mere men?

Where are we still relying on the flesh to get us through our day-to-day instea of relying on God? This is where we are still depending on God's milk to feed us. We are starving our Spirit, our Spirit needs milk early on, but there comes a time when, like a child, more than milk is required to sustain us.