1 Corinthians 2:16
[Isa. 40:13 says], "For who knows [what is in] the Lord's mind? And who is capable of instructing Him? But we have the mind of Christ. [Note: The "we" may refer to the apostles, who had the gift of inspiration (See verse 12), or to all Christians who have spiritual discernment].
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.
Romans 11:34
[Note: The following are rhetorical questions raised from their reading of the Old Testament]. For who has known [what goes on in] the Lord's mind? Or, who has been His advisor?
John 16:13-16
However, when the Holy Spirit of truth comes, He will lead you [apostles] into all the truth. For He will not speak on His own authority, but will speak [only] what He hears [from the Father]. And He will tell you about the things that are to come.
John 17:6-8
I have revealed your name [i.e., your power and character] to the men you gave me out of the world [i.e., the apostles]. They belonged to you, but you gave them to me, and they have obeyed your word.
Ephesians 3:3-4
[It is] that God's secret plan [i.e., revealed in the Gospel preached to Gentiles. See verse 6] was made known to me by way of a revelation. [See Acts 9:15; 22:21]. I have already written to you [about this] briefly [i.e., probably a reference to 1:9ff].