The pox viruses (presumably from childhood chicken pox) continue to live in the nerve endings of the main nerves coming out of the spinal cord, especially those of the head, neck and dorsal and ventral rib cage. Stress or a bout of some other disease that stresses the immune system causes the humoral and cellular defenses around the nerve endings to decrease, and the latent pox viruses express themselves (only locally around the individual nerve ending, not systematically). So the shingles re expressed as red bumps, usually in the middle of the chest or the back, or on the neck or the face. But this triggers the immune system to mount a new attack against the viruses, sometimes with a little damage to the individual nerves that hve been hosting the viruses. However, the new immune attack causes a "re-education" of the immune system (something like a booster shot for certain vaccines), and that usually redoubles the body's defenses against the pox virus. Hence, it is usually kept from recurring, unless a very severe immune-compromise situation occurs in that person's body and a second or even third bout of shingles can occur.

Mammal is not defined by having hair. Mammal is defined by having "mammary glands" to feed the live-birth young. Mammal:mammary. The hair just happens to be a shared charcteristic because of the very small number of species of mammals that evovled in late cretaceous, running around the feet of the dinosaurs. From those few mammal species that evolved back then (AKA a bottleneck in mammalian diversity), the rest of the mammals we know on earth evolved to fill other niches. This diversification carried with it the trait of hair, although in certain environments it would be useful to lose the hair for better survival (e.g., whales or dolphins underwater to decrease drag for swimming). So it makes sense for some mammalian species to lose the hair for survival purposes.

Much of what people consider to be the devine word of God comes from their belief in their holy book. If you are a Christian and you look to the Bible for answers, you are taking the teachings it has to give you based on what Jesus and God have asked of you for believing in them: namely, to have "faith". Your "Faith" in God and your "Faith" in Jesus is the same as your "Faith" in the truthfulness of the Bible. If you could actually "prove" God or "Prove" Jesus or "Prove" the truthfulness of the Bible, you would no longer have "Faith", because "Faith" means to have an "unproven belief" that something is true. People have faith in God. People have faith in Jesus. People have faith in the Bible. Were we to actually prove all of it true, you would lose the value of your "faith" in all of it. It would all just become another part of all the data we already have in our secular world. Even if you could prove the whole of the Bible true, the power within it and within God and within Jesus happens to be in our Faith in them, not the necessity of their truth.