Jesus at several instances said: You see, but see not. You hear, but hear not. Once facing the Pharisees and Scribes he exclaimed: “I speak that which I have seen with my Father: and ye do that which ye have seen with your father” (John 8:38).
My testimony in this context is: I see and hear on the sense level seeing/hearing my life, my emotions, my reactions and actions and at the I same time I see and hear within my spirit, and what I see and hear on this level is what I see and hear on the sense level. By faith I see what my Father is doing, but this seeing isn't outer sense-seeing. But, with my natural senses I see how He comes out of me. This is what I believe Jesus was referring to when He spoke to the Pharisees and the Scribes.
James said that if the source is clean the fountain will be likewise. Spirit is too deep for us which means that without revelation we will continue to walk in the delusion that what we see with our natural senses is all there is, and hence we will judge accordingly. In other words; we see, but see not and hear, but hear not. Some authors speak about the extended senses, which is nothing else than faith seeing and hearing, that is, a recognition of that the facts of being are found in the invisible. Faith deals with these facts. It sees what is beyond the scope of our natural senses.
God’s invitation is always: “Come up on higher!” This invitation leads to, for us, new faith choices which if responded to take us further into uncharted territory. We learn to hear and hear, and to see and see. Why is this important? Because, God desires to lead His sons to maturity knowing who they are. A safe son’s testimony is: “I speak that which I have seen with my Father” no matter outer appearances. A safe son knows that he is kept by the Father and that the Father does the works.
Jesus knew Who His Source was and He knew that if the Source was pure the fountain would be clean. The Pharisees saw, but didn’t see and thus based their judgment on performance and what they saw with their natural senses not knowing that if their source, their father, was unclean their doings would be of the same quality. Jesus in one instance said about the Pharisees: “You are like whitewashed tombs, which look beautiful on the outside but on the inside are full of dead men's bones and everything unclean.”
Jesus’ “who by taking thought can add one cubit unto their stature” makes perfectly sense when we know that all things starts in the invisible and that our Father is the responsible One in this spirit/Spirit union, and, further, that we are the temples through which He has found a point of expression.