It seems to be there are several possible points of discussion. Are you interested in discussing whether your second premise is a true assertion? Or would you focus on the first, that is, whether voluntarily chosen believes entail responsibility? Or perhaps, since you qualify the argument with "to a degree", then the question arises, "To what degree?"

But if we are able to understand and affirm--and thus voluntarily choose--a belief, then of course we are responsible for it, whether arrived at by direct or indirect means. From what I understand, there really isn't much controversy about whether indirect voluntarism is possible, and so it follows that, yes, we can be held responsible for what we believe, to the degree that our beliefs are voluntary.