Can a saved person still be a babe in Christ who doesn't understand who God really is?
Yes. Scripture shows that the Corinthian believers were saved yet still babes in Christ, lacking full comprehension of who and what God really is. It also states that many believers today are saved but remain babes in Christ with no comprehension of who God really is.
Les teaches that the issue here is not salvation but knowledge. The Corinthian believers were genuinely saved, yet they remained babes in Christ and did not yet have full comprehension of who and what God really is. He says many believers today are in the same condition: saved, but still babes with no comprehension of who God really is. Earlier he notes that if anyone thinks he knows anything, he knows nothing yet as he ought to know; when we think we have learned it all, we are just getting started, because the things of God are unfathomable. Yet those who love God are known by Him on a first-name basis, and He knows their needs before they ask. The passage contrasts the many so-called gods and lords with the one God the Father and one Lord Jesus Christ, the Creator of all.
Howbeit there is not in every man that knowledge: for some with conscience of the idol unto this hour eat it as a thing offered unto an idol; and their conscience being weak is defiled.