I would argue that not only is belief in what you are doing important, but important to the exclusion of everything else done in ritual. I have done magic without ritual of any type, had results, and never doubt it. That is the most important thing that there is in magic, belief. Everything else is just to help you focus that belief. If you have utmost belief, you can do away with all the crutches.
Wouldn't you agree?
Bloodsong
Wouldn't you agree?
Bloodsong