1 Cor 2 explains that it is not by man's intellect, but only through the teaching and guidance of the Holy Spirit that man gains spiritual wisdom and maturity in the spiritual truths of God. Even the message of the gospel is received as foolishness if given only by the fancy persuasive eloquence of human wisdom. Paul says he preaches the gospel very simply and plainly and rests on the work of the Holy Spirit. God's truths are "revealed to us by His Spirit, and ...His Spirit shows us even God's deep secrets" (v.10). "We have not received the spirit of the world but the Spirit who is from God, that we may understand what God has freely given us" (v12). Nobody can know what the Lord is thinking , but we can have some insight into His thoughts by the illumination from the indwelling Holy Spirit. "We have the mind of Christ" (v.16). I'm guessing that this doesn't just happen passively (ie. while we are sleeping), but requires regular time of fellowship with God in His word, and talking and listening to Him.