Matthew 13:11-12
He replied, "You disciples are being given an understanding of the secrets of the kingdom of heaven, but the crowds of people are not.
John 6:45
It is written in the prophets [Isa. 54:13], 'And they will all be taught by God.' [So], every person who has heard the Father and learned [from Him] will come to me.
John 7:17
If anyone [really] desires to do what God wants, he will know whether my teaching comes from God or whether I am speaking on my own authority [only].
1 Corinthians 2:14-15
Now the natural person [Note: Since this person is contrasted with the spiritual person of verse 15, it is taken here to mean the person without the Holy Spirit] does not receive the things [i.e., truths] revealed by the Holy Spirit of God, because they are [considered] foolishness to him. And he cannot understand them because they must be discerned by using spiritual judgment [i.e., judgment aided by the Holy Spirit].
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.