knowledge at its highest reach: the complete knowing that belongs to God, and the recognition of God that people are given and taught
Hebrew has a common, all-purpose word for knowledge (דַּעַת), which stretches from a craftsman's skill to plain good sense to knowing God. This word is its rare relative, appearing only six times, and it keeps to weightier ground. Every one of those six places has to do with God: what God himself knows, what a people comes to know of him, or the teaching that hands that knowing on.
Twice the word is plural, once of God ("a God of knowledge," 1 Samuel 2:3) and once in Elihu's claim that someone "perfect in knowledge" is present (Job 36:4). The plural is not counting separate items of knowledge. In Hebrew poetry a plural like this heightens the idea, so it means knowledge in its fullness, the kind that leaves nothing out and misses nothing.
The most famous verse is Isaiah 11:9, where the earth will be as full of the knowledge of the LORD as the sea is of water. That is not a promise of more religious information. It pictures a whole world that finally recognizes God for who he is and lives accordingly, which is why Jeremiah 3:15 can speak of shepherds feeding a people with this knowledge as their basic job.
A close partner noun (דֵּעַ) turns up only in Elihu's speeches in Job, and he uses the two almost side by side, saying "perfect in knowledge" with one word in Job 36:4 and with the other, of God, in Job 37:16. That partner word also stretches to cover the opinion a speaker is putting forward, which this one never does.