Not True everyone can understand the milk of the word.Milk and solid meat can ONLY be received by saved persons!
1Co 3:1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.
MB1Co 3:2 I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able.