Hebrews 5:12

1 Corinthians 3:1-3 NIV
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. I gave you milk, not solid food, for you were not yet ready for it. Indeed, you are still not ready. You are still worldly. For since there is jealousy and quarreling among you, are you not worldly? Are you not acting like mere humans?

1 Peter 2:2 NIV
Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation,

Hebrews 5:13 NIV
Anyone who lives on milk, being still an infant, is not acquainted with the teaching about righteousness.

Hebrews 6:1 NIV
Therefore let us move beyond the elementary teachings about Christ and be taken forward to maturity, not laying again the foundation of repentance from acts that lead to death, and of faith in God,

Isaiah 28:9-10 NIV
“Who is it he is trying to teach? To whom is he explaining his message? To children weaned from their milk, to those just taken from the breast? For it is: Do this, do that, a rule for this, a rule for that ; a little here, a little there. ”