A key concept in understanding the kingdom of heaven is the concept of dimension. We are taught in school that a point is one dimension, a plane is two dimensions, and a cube is three dimensions. So far so good. We also know that a shadow cast by a three dimensional object has only two dimensions. For example, the shadow cast by a cube is a square and a shadow cast by a sphere is a circle. The cube or sphere is the higher dimensional reality while the square or circle is the lower dimensional reality. The cause and origin of the lower dimensional reality is the higher dimensional reality. In like manner, a four dimensional reality would cast a three dimensional shadow and a five dimensional reality would cast a four dimensional shadow. Plato told us thousands of years ago that material reality is the shadow of a higher dimensional spiritual reality. Spiritual reality is the cause and origin of our time-space material reality. What we think is real (physical reality) is just a shadow and what we cannot see directly is the real thing. How can we perceive better this higher dimensional spiritual reality that lies beyond our material senses? Fortunately Jesus has told us that spiritual reality is located within. He calls this spiritual reality "the kingdom of heaven."
Luke 17:21Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you.
Now we understand why Jesus says that he is from above. Spiritual reality is a higher dimensional reality than material reality which therefore is below. Now we can understand why the kingdom of heaven is both above and within. No wonder there was confusion. Modern man is better prepared to understand. Our physicists tell us that physical reality probably has ten dimensions rather than just the three we see. When using ten dimensional mathematics the equations of physical reality become greatly simplified. Things look so complicated to us because we are just seeing shadows of a higher order reality. As a corollary, increasing simplicity of expression is a hallmark of higher order reality. The book "Flatland" explores this topic further for those interested.
Total reality has three main levels. Physical, mental, and spiritual. Physical is to a point what mental is to a plane and spiritual is to a solid. Shorthand for this is point/plane/solid is as physical/mental/spiritual is as level 1/ level 2/ level 3. Now consider fact/meaning/value is as to physical/mental/spiritual is as to what/how/why. This means that spiritual causes result in physical events or facts that are understood by the mind. Next consider: action/decision/purpose and thing/meaning/value. Spiritual values through acts of will result in mental decisions which cause physical behaviors--- body/mind/spirit. When Gods will becomes mans will, the kingdom of heaven becomes manifest in the world. These hierarchical dimensional levels allow us to unify and harmonize all aspects of real experience.
The time has come