Leaving the cancer is stressful--along the lines of quitting smoking. As with quitting smoking, you are going to feel pain. With the religion, it is guilt, houndings, being cut off from family, and finding time on your hands with nothing to fill it with. Your routine is disrupted. For many, the religion is entwined with their living arrangements (their landlord is a witless) and/or job (their boss or customers are witlesses). They might lose one or both of these as well.
But, like quitting smoking, the end result is better. After the distress winds down, you can start in peace. There is no longer a drain on your money and time, and you can watch whatever you want and listen to whatever you want without the hounders stopping in. You lose the guilt of not being in field circus--the end of the month goes by without you doing any field circus, and you don't give a fxxx. You also gain back the ability to think for yourself, and the results are often better than what you had been getting when the witlesses were doing your thinking.