How did medieval peasants read the Bible? I heard something on the lines of the churches used the statues of demons on top of churches to scare people of what awaits them if they sin, but could peasants themselfs purchase a Bible? If so how much was it?
Statues of demons might be a bit of an exaggeration, but European literacy rates were drastically lower during the period compared to the modern day. As a result, a lot of Biblical instruction was done in other ways, to accommodate an illiterate populace. In addition to the oral tradition - not just sermons, but a parent retelling Biblical stories to their children - churches often featured works of art that attempted to teach the Bible through visual storytelling. Famous scenes and events would be recreated, not just in sculptures or statues of demons, but through paintings, and even stained glass. It wasn't just peasants that relied on oral and visual storytelling to learn about their religion, but many nobles as well also struggled with literacy. Many peasants did not read the Bible - they were shown it and taught it.
In regards to buying a Bible, such a thing would be incomprehensible for most. The advent of the modern book, as we know it, can be traced back to development of moveable print. Here in the west, that correlates with Johannes Gutenberg, who developed the Gutenberg press in the second half of the 15th century. For most of the Medieval period, books were created by hand. Not only was this an arduous and time consuming process, but it could only be done by a select few, due to the above-mentioned low literacy rate. As a result, most books that were made were treated more like works of art, with extensive effort put into decorating the words and the pages (search for "illuminated manuscripts" if you want to see examples). Books were rare, highly treasured objects. It was not something that a peasant could simply buy, even if they could read and wanted to do so.
In regards to the cost of a book, that somewhat depends on time, region, and the size and quality of the book. In England, a relatively inexpensive book could cost you 53 shillings (an example from Intertexts: Studies in Anglo-Saxon Culture). Comparatively, according to Dyer, a thatcher living in England could expect a daily wage of two pence in 1261, and of four and a half pence in 1400. Even taking the secondary salary into consideration, a shilling was equal to 12 pence, meaning that a 53 shilling book was equivalent to 636 pence, or just over 141 days' wages for a thatcher in 1400, and more than twice that in 1261, comparatively. That means that a single, relatively inexpensive book could represent half a year or more of a thatcher's wages. A Bible would be even more expensive, and well out of the price range of all but the wealthiest among the populace before the printing press.
To conclude with a quote from The Cost of Books in Chaucer's Time, "There were fewer books in all England in 1390 than there are in many single libraries today" (6).
Bibliography:
Charting the "Rise of the West": Manuscripts and Printed Books in Europe, A Long-Term Perspective from the Sixth through Eighteenth Centuries in The Journal of Economic History, Vol. 69, No. 2
The Cost of Books in Chaucer's Time in Modern Language Notes, Vol 48, No. 3 by Wilbur Lang Schramm is a fantastic resource if you want to read more on this topic. It has several additional examples of different books, and what they might contain, as well as the prices of each and some basic conversions. Some books are slightly below the example from Studies in Anglo-Saxon Culture, while some are many times more expensive.
Education in Twelfth-Century Art & Architecture: Images of Learning in Europe, circa 1100-1220 by Laura Cleaver, Julian Luxford, and Asa Simon Mittman
Intertexts: Studies in Anglo-Saxon Culture presented to Paul E. Szarmach
Standards of Living in the Later Middle Ages by Christopher Dyer
Hi! The vast majority of Medieval peasants could not read at all, let alone write. Peasants could never hope to purchase a bible themselves, it was far more likely that their local church or priory would have one and that would be a treasured community object (especially in earlier centuries). I can't give you exact costs, but they were exorbitantly expensive.
The Catholic use of statues and imagery was , yes, to play into the visual aspect of learning and morality. One reason for illuminated manuscripts was to pass along the knowledge and stories that were written down in a way that did not require being literate. This was especially accomplished when it came to regularized depictions of saints and scenes, such as the Virgin Mary wearing blue.
Not only that, but most writing would have been done exclusively in Greek or Latin, languages that peasants may have heard in the Mass but not learned at all. This type of education was reserved for clergy and nobility (possibly merchants) for the most part. There are of course outliers and unique experiences, but the majority of peasantry and lower classes as a whole were illiterate. Even Charlemagne himself was unable to write.
One of the biggest reasons for the Protestant Reformation in the Renaissance was precisely because of these situations. Protestants championed the idea of holy texts being written in the vernacular: German, English, French, Spanish, etc. Catholicism retained the idea that the words of God should be kept in Latin to avoid interpretation from those who were outside of the clergy.
There are a million other things I could go into with this, but I've tried to be as brief as possible! I hold a degree in History with a focus on Medieval and Renaissance Europe. The idea of Medieval literacy is ever growing and changing with more research, I do recommend doing some reading!
Some Sources (some are academic and therefore access may be limited):
https://www.journals.uchicago.edu/doi/abs/10.2307/2847287?journalCode=spc
https://www.academia.edu/download/54287702/Camille_Seeing_and_Reading.pdf
https://www.britannica.com/art/illuminated-manuscript
https://www.metmuseum.org/toah/hd/arch/hd_arch.htm
Edit: Grammar!