The sort of belief you mentioned is not a belief nor a feeling, it is exactly what it is - a hypothesis, lacking conclusive evidence, yet appears to be a logical conclusion born of certain arguments and facts that support it.

Therefore, “I support the idea of”, or “I recognize that”, or “I feel that” are much more appropriate than “I believe that”. You can paint in whatever shade of certainty you wish.

“Knowing” is just the highest level of confidence in the hypothesis.