Mark 4:11
He said to them, "You disciples are being given an understanding of the secret of the kingdom of God, but to outsiders everything will be told in parables.
Mark 4:34
And He did not speak to them [i.e., concerning the kingdom] without using a parable, but He explained everything to His own disciples privately.
John 15:15
I do not call you slaves anymore, for a slave does not know what his master is doing. But I have called you friends, because I have told you everything that I heard from my Father.
Colossians 2:3
In Him all the treasures of wisdom and knowledge are hidden.
Hebrews 4:12
For God's word is alive and active and sharper than any double-edged sword. It penetrates [deep enough] even to divide [a person's] soul [from his] spirit, and his joints [from his] bone marrow [Note: This is figurative language describing the penetrating effect of God's word into a person's spiritual, inner being] and is able to judge the thoughts and intentions of a person's heart.
James 1:5
But if any one of you lacks wisdom, he should pray to God, who gives to everyone generously and does not begrudge [the person who asks], and it will be given to him.