Can we know the mind of God?  Not on our own.  Not by our conjecture.  We know God through the Spirit of God.  He shows us Jesus.  He shows us the mind of God; He reveals the thoughts of God.  True spirituality is derived from being in contact with God through the abiding presence of the Holy Spirit.  It is the Spirit who gives us spiritual discernment and spiritual understanding.  We desperately need this in our personal lives; we must have this in our churches. 

“For who among men knows the thoughts of a man except the man’s spirit within him? In the same way no one knows the thoughts of God except the Spirit of God.  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.  This is what we speak, not in words taught us by human wisdom but in words taught by the Spirit, expressing spiritual truths in spiritual words. The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned. (1 Corinthians 2:11–14 NIV)

(From “Sonlight for the Soul”, by H. Lamar Smith)