Surely not.
"I can believe a thing without understanding it. It's all a matter of training."
--Dorothy Sayers, in Have His Carcase
This is a rather nice line, and quoted on the web, apparently, more than I would have expected.
But I think she is wrong.
Not just because THINKING I understand is not full comprehension. You can quibble - I often do quibble. But my electronics teacher said as how a calculation coming out to within 10% will in most circuits be as good as spot on. An approximation to understanding - the best I can do, how about you? - that allows one to operate without significant error is pragmatically equivalent to full comprehension - and a whole lot easier to attain.
But I think belief without understanding depends primarily on innate disposition. If training is involved, I see it as secondary.
I can and do believe some things I understand, and understand much that I do not believe.
I can and do believe some things I do not understand [like I believe some creationists and evolutionists think the other is out to GIT them, though I do not understand that].
Of course there are things I do not understand [yet] that I do not believe [yet] - but that is trivial.
There do seem to be some who will not believe what they do not understand. There may be some who will not DISBELIEVE what they do not understand.
But I have never met anyone for whom training appeared to be a factor.