You need to be in proper gear when you are driving down a hill because you are only required to use the brake hard enough to get a slowdown. It can be tricky to go down a hill when you 're not an adept driver. This may be a task that you can allow other people to do if you feel that you cannot do it.
Remember that your safety is always on the line while you drive. Even if you would have all of the right gear, there is no guarantee that you will stay safe the whole time that you are driving. Changing gears while going downhill is not an easy feat to do.