You can definitely stop using soap. It's not a necessity for maintaining cleanliness, especially for your body. Water alone can effectively remove dirt and grime. However, some people might find that they need to use soap for specific areas, such as their hands, due to potential exposure to germs and bacteria.
While using soap might be a deeply ingrained habit, it's not essential for everyone. There are many people who have successfully transitioned to using only water for their hygiene routine. The key is to pay attention to your body's signals and adjust your routine accordingly.