Original Verse:
1st Corinthians Chapter 3 Verse 1And the teaching I gave you, my brothers, was such as I was able to give, not to those who have the Spirit, but to those who are still in the flesh, even to children in Christ.

Reference Verses:
Hebrews Chapter 5 Verse 13For everyone who takes milk is without experience of the word of righteousness: he is a child.
John Chapter 16 Verse 12I have still much to say to you, but you are not strong enough for it now.
Ephesians Chapter 4 Verse 14So that we may be no longer children, sent this way and that, turned about by every wind of teaching, by the twisting and tricks of men, by the deceits of error;