The Religious Affections - Appendix - Duty To Believe on Jesus Christ etc

Letter to Thomas Gillespie, pastor in Scotland. 9/4/1747
But I conceive that there is a great deal of difference between these two things, viz. its being a man's duty that is without spiritual light or sight to believe, and its being his duty to believe without spiritual light or sight, or to believe while he yet remains without spiritual light or sight. Just the same difference that is between these two things, viz. its being his duty that has no faith to believe, and its being his duty to believe without faith, or to believe without believing. I trust there is none will assert the latter, because of the contradiction that it implies. As it is not proper to say, it is a man's duty to believe without faith, because it implies a contradiction, so I think it equally improper to say it is a man's duty to believe without these things that are essentially implied in faith, because that also implies a contradiction.