Answer:
A neuron is analogous to an electric wire. If you look at an electric wire going from a lamp to a wall plug, you do not see the actual wire. Instead, you see the insulation. If you would scrape off the insulation, you would see two wires. If those two wires touched you would hear a loud pop. Then a circuit breaker would throw. The wire would be just as good as it was before you removed the insulation. The wire carried the electricity. The insulation protected the wire and let it do its job. Without the insulation, the bulb would not work.
The Myelin sheath protects the nerve from outside forces. It lets it carry its signal free from outside influence. It is a piece of insulation.