You raise an interesting Biblical concept, milk vs. meat. I have done a little research into this theme through the Bible and feel it is helpful in identifying heresy and idolatry.
Bible study is an important prerequisite:
2 Timothy 2:15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.
It appears that your reference is Hebews 12 - 14:
Heb 5:12 For when for the time ye ought to be teachers, ye have need that one teach you again which [be] the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. 13 For every one that useth milk [is] unskilful in the word of righteousness: for he is a babe. 14 But strong meat belongeth to them that are of full age, [even]
those who by reason of use have their senses exercised to discern both GOOD AND EVIL.
I know that the evil that I am detecting is
idolatry and heresy. The Bible speaks to this inquite a few verses:
1Co 10:7, 14 7 Neither be ye idolaters, as [were] some of them; as it is written, The people sat down to eat and drink, and rose up to play. ... 14 Wherefore, my dearly beloved, flee from idolatry.
Psa 135:15 15 The idols of the heathen [are] silver and gold, the work of men's hands.
Isa 2:8 Their land also is full of idols; they worship the work of their own hands, that which their own fingers have made:
Eze 20:16, 24 16 Because they despised my judgments, and walked not in my statutes, but polluted my sabbaths: for their heart went after their idols. ... 24 Because they had not executed my judgments, but had despised my statutes, and had polluted my sabbaths, and their eyes were after their fathers' idols.
Rev 9:20 And the rest of the men which were not killed by these plagues yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: which neither can see, nor hear, nor walk: