The ability to turn off the soul channel is called free will. There's also a tendency to want to turn off the soul, to shut out God. This tendency or inclination is called by many names in Judaism. The most common is the yetzer hara ("evil inclination"). This is also part of human nature.
A famous that helps us understand the struggle between what the world's religious traditions have called "good" and "evil":

Once a rabbi pleaded with God to show him heaven and hell. God agreed, and transported the rabbi to a door that bore no name. He trembled as he saw it open before him, into a room where all was prepared for a feast. There was a table, and at its center a great dish of steaming food. The smell and the aroma inflamed the appetite.

Diners sat around the table with great spoons in their hands, yet they were shrieking with hunger in that terrible place. They tried to feed themselves, and gave up, cursing God. For the spoons God had provided were so long that they could not reach their faces and get the food to their tongues. So they starved because of these spoons, while the dish of plenty lay amongst them. The rabbi knew their shriekings were the cries of hell, and as knowledge came, the door closed before him.