Deuteronomy 29:4 says,  “Yet the LORD has not given you a heart to perceive and eyes to see and ears to hear, to this very day.”  What a strange statement, if God did not enable the people to perceive what God was doing, then it would seem like God would be at fault for them not understanding what was happening in the kingdom of God.  However if God is at fault, then could these people later stand up and accuse God saying, “God I would have understood but you did not let me. “You failed to give me a heart to understand and You failed to give me the ability to perceive”?
In Psalm 81:11,12 God speaks about His rebellious people, how He had promised to provide good things for His people, “But My people would not heed My voice, And Israel would have none of Me. So I gave them over to their own stubborn heart, To walk in their own counsels.” The people had no desire to walk in God’s ways so God gave the people over to what they wanted.  The fault was not on God, but rather that the people did not want to understand, they were content not being close to God, they were content with Moses relating with God and them staying distant.  “You speak with God and we’ll stay distant”, is what the people said in Exodus 20:19,20; Deut. 18:16.  So God gave them what they wanted.
The ability to understand the things of God is a gift of God.  God discreetly enables those who want to understand Him, the ability to understand. Our eyes and ears will be unable to perceive God until we openly come to the Lord, He then enables us to see and understand more of Him, if we really want to. The challenge is, do we really want to understand and relate to God under His conditions, or do we want to under our own conditions?