An arrogant, prideful, egoistic, religious person who believes his/her religion is the only true religion. They are deeply religious in their dogma/religion to such an extent they believe that is who they are. They are often times very legalistic and think they are better than others, especially other people who aren't members of their particular religion. People who are religionists are usually the biggesthypocrites.
Religious people are often times religionists due to the effect their religion has had on them over the years.
Jenny is so prideful about her religion, she is such a religionist.
2: Someone who believes that religion or the belief in a higher power drives some people to terrible things, and while not all people will go to the same extremes the small amount of comfort given by religion is not worth the pain created by it.
3: A person who bases their life and ideas on fact.