The 100 trillion or so cells that make up the human body perform countless activities, without ever stopping, growing tired or needing a rest. In the same way that every living thing needs energy—and therefore, food—to survive, so the cell also needs various nutrients in order to perform its countless functions. In the same way that raw materials to be used in production are carried inside a factory and stored until needed, and waste products are later sent out of the factory later, so a very complex production, storage and waste-disposal system operates within the cell.
In the same way that the qualities of the raw materials brought to the factory are specified by contract, so the cell observes special conditions for the substances it takes into itself. Substances do not enter the cell at random. As if they were already familiarized beforehand, these molecules are subjected to “identity checks” at the cell membrane. There are entryways held open solely for substances regarded as admissible. Other substances, whose entry is regarded as possibly undesirable, are eliminated with a care reminiscent of fingerprint checks. The way the nature of these materials is checked and confirmed before entering the cell is of vital importance. These strict security precautions avoid the risk of entrance of any virus, bacterium or poisonous substance into the cell. This huge responsibility is assumed by the thinnest of membranes.
Each one of the trillions of cells that make up your body acts with this awareness. Each cell membrane implements this sensitive selection mechanism in that part of the division of labor that falls to it. No human being can even be aware that such extraordinary functions are taking place, let alone be able to perform any such selection consciously. The appearance of an intelligence beyond human in the cell membrane shows that the source of that intelligence is not the cell itself but rather the inspiration of Allah, Who created it. By the command of Allah each and every cell carries out its duties for us flawlessly.