When I was in elementary school we were given a project to demonstrate osmosis. We carefully peeled the shell off the big end of an egg, inserted a plastic or glass tube in the pointed end, and immersed the egg halfway into a glass of water. Within a day or so, the innards of the egg had been dramatically forced up into the tube. In high school biology class we were told that in the process of transpiration, water is raised from the roots to the leaves in trees by osmosis. Then in college physiology class, we learned that water is absorbed by osmosis through the intestinal wall into the blood. So, what is this mysterious process of osmosis? The dictionary defines the word as the tendency of a solvent to pass through a semipermeable membrane so as to equalize the concentration of two solutions. Thus the water in the glass passes into the egg in an attempt to dilute the contents. The water passes into the root of the tree in an attempt to dilute the sap The water passes through the thin walls of the cells lining the intestines in an attempt to dilute the blood.
This process of osmosis produces what is called "osmotic pressure;" it is the force that pushes the yolk of an egg up the tube against the force of gravity; it is the root pressure that forces tons of water hundreds of feet up a tree trunk against gravity; it is the force that pushes water through the intestinal walls against the pressure of the blood. Osmotic pressure is defined as the pressure exerted by a solvent passing through a semipermeable membrane in osmosis. But. you might ask, what is a semipermeable membrane? It is a thin porous membrane that allows smaller molecules (like water) to pass through, but not larger molecules (like salt or sugar} to pass through. A semipermeable membrane is very selective as to what it lets through.
We have the protection of a spiritual semipermeable membrane; information enters our brains through the five senses: sight, hearing, tasting, feeling, and smelling. These are sometimes called "the avenues to the soul." The sensory perceptions of our environment are indelibly imprinted on the neural pathways of the cerebral cortex, commonly called memory. Even if we cannot consciously recall them, they are there, lurking to influence our thinking and behavior at some unexpected time. But, we have a choice as to what information gets through to our memory bank. We have a conscience and we have the power of decision. This is the semipermeable membrane that is designed to filter out the undesirable and allow the entrance of what is "true, pure, right, holy, friendly and proper (Phil. 4:8, CEV). This application of the conscience and the will I wish to call "spiritual osmosis."
