The New Testament texts speak alternatively of seeing the Kingdom of God and entering the Kingdom of God.

Seeing and entering the Kingdom of God

To see the Kingdom is to theoretically or conceptually grasp it. Most Chrisitans are not even aware of the kingdom at this level.

However entering the Kingdom is far more than seeing.  To enter the Kingdom is to experientially know it (gnosis). 

A soft  heart is the difference between seeing the Kingdom, and experiencing or entering the Kingdom of God.