He believed that there is only knowledge or ignorance

This seems to be an untenable proposition. Even without looking at the world of religious faith we have to make some decisions on the basis of evidence and probability.

My sentiments exactly. Just because words like belief and faith are most widely used in a religious, or at least spiritual, context, does not mean that they are limited to such uses. I believe that Arsenal is capable of winning the English Premier League, and I try to have faith that they will.