It’s often a big move as assumptions can be long-learned automatic responses and established opinions. In such a case there is no way, that doubt will appear, assumptions feel like truths. People are unaware that things could be different.
Sharing assumptions will often appear as moralizing. They are shared as the right thing to do or accept. It makes assumptions the perfect ground for fears.
Beliefs on the other hand are, as a friend described it today, thoughts we currently believe to be true. It means that we are aware that we don’t know for sure. We see and know that others might have another idea. Sharing our belief becomes an act of courage and vulnerability.
The next step is the willingness to investigate interesting arguments challenging our beliefs.