The Christian Classics Ethereal Library has a nice version of The Pilgrim’s Progress available free online. There are also some links to print editions of the book. The online version has a number of links inline which connect John Bunyan’s metaphors to the actual passages of scripture which inspired them. This shows even more how much the Bible entered into the heart and life of this godly man.
It’s been said that the two books which were found in most homes in the USA during the 1800’s were the Bible and The Pilgrim’s Progress. Of all the classic books by Christian authors that I’ve read, it has probably the most amount of material that is truly common to all Christian theological persuasions. There is very little for any evangelical Christian of any theological stripe to disagree with at any level. There is a huge amount of insight and understanding of Christian experience throughout, and a great deal of significance for pastoral ministry in the characters which Bunyan sketched.
In an era when many believers neglect the classics for the latest Christian best seller, the video teaching or the popular radio preacher, Bunyan has probably more to say to a larger audience of believers than any contemporary author. Sadly, there are probably more evangelical believers who know more about the Paul Bunyan legends and the Pilgrims from Plymouth, Massachusetts than who know about John Bunyan and The Pilgrim’s Progress.