How did Christians cultivate their knowledge of the Bible before mass-printing of the Bible? The Bible is by far the most sold book ever. As this site says:

Bible Society’s attempt to calculate the number printed between 1816 and 1975 produced the figure of 2,458,000,000 – almost 2 and a half billion.
Another survey, for the years up to 1992, put it closer to 6 billion.

Nowadays, we could argue that most of Christians (families) own a Bible. But more importantly, most of Christians can read, which mean they, in principle, can read and study the Bible.
However, this has not always been the case. On the one hand, for most of the last two millennia, most of the people were illiterate. The existing data shows that literacy in now-developed countries started to improve only by the Enlightenment period, reaching +80% less than 200 years ago. Such levels of literacy in majority Christian countries of Latin America were only reached less than a century ago:

On the other hand, the availability of Bibles, particularly before the invention of the printing press and the &quot;Gutenberg revolution&quot;, was quite constrained. Before the invention of the printing press, bibles were manually copied, primarily by monks. This was a time consuming process, making bibles quite expensive. Thus, bibles were perhaps primarily available in churches, monasteries and some rich individuals' houses (who were the ones that could read, anyway).
So, the question I have is, how did the majority of Christians cultivated their knowledge of the Bible (OT and/or NT)? Probably, one of the original intentions of the writing of the gospels was to make Jesus' teaching and life more widely available for Christians across churches. With the establishment of the Canon of the Bible, this process became mainstream across the established Church (e.g. the commission of the Vulgate by Pope Damasus I).
My intuition tells me that most of Christians learned about the Bible by popular sayings, stories, and calendar celebrations (like Christmas). Those who attended a church service or Mass would learn also from the lectures and sermons. Is there a formal/historical analysis of this situation? Perhaps a book that goes through this?
How did Christians cultivate their knowledge of the Bible before mass-printing of the Bible?

There are several ways the poor and illiterate were able to cultivate a basic knowledge of the Bible prior to the advent of the printing press.

Some of the most obvious tools used by the faithful were stained glass windows, paintings, statues, story telling, missions, medieval mystery plays and the use of song. 

We all know that the Poor Man's Bible is stained glass windows that could be found in many different churches and cathedrals.


  The term Poor Man's Bible has come into use in modern times to describe works of art within churches and cathedrals which either individually or collectively have been created to illustrate the teachings of the Bible for a largely illiterate population. These artworks may take the form of carvings, paintings, mosaics or stained glass windows. In some churches a single artwork, such as a stained glass window has the role of Poor Man's Bible while in others, the entire church is decorated with a complex biblical narrative that unites in a single scheme. - Poor Man's Bible (Wikipedia)




Images above are of Noah, Lamech, and Thara, from the Ancestors of Christ Windows, Canterbury Cathedral, England.

Singing was one of the greatest ways to enhance one's knowledge of the Bible and it is explicitly mentioned in Scriptures. 


  1  Sing to the LORD a new song, for he has done marvelous things; his right hand and his holy arm have worked salvation for him.   2  The LORD has made his salvation known and revealed his righteousness to the nations.   3  He has remembered his love and his faithfulness to Israel; all the ends of the earth have seen the salvation of our God.   4  Shout for joy to the LORD, all the earth, burst into jubilant song with music;   5  make music to the LORD with the harp, with the harp and the sound of singing,   6  with trumpets and the blast of the ram’s horn— shout for joy before the LORD, the King.   7  Let the sea resound, and everything in it, the world, and all who live in it. - Psalm 98:1-7


Story telling has a huge place in all this. It is recognized by historians and theologians that Israel's history was preserved by word of mouth.


  By the middle of the 5th century BC religion and history were taught simultaneously through storytelling. These topics were made fascinating by way of the storyteller. Their lessons were taught through exciting recounts of miracles, by games of question and answer, and by visible reminders (Nelson 2002, 332). They explained the meaning of the great feasts to them and showed them how each of the customs that they observed had holy significance (Daniel-Rops 1962, 128). Even a simple pile of rocks became an object lesson for the retelling of the crossing of the Jordan River. Fathers told their children of all the wonders that God had done for his people. The Scripture was the foundation of all morality. Therefore, to study and learn it was to grow spiritually (Ward 1987, 150). - STORYTELLING: A SOURCE FOR REDUCING BIBLICAL ILLITERACY


Another way to enhance the knowledge of the Bible was through  Medieval Mystery Plays or as some call them Miracle Plays.


  Mystery plays and miracle plays (they are distinguished as two different forms although the terms are often used interchangeably1) are among the earliest formally developed plays in medieval Europe. Medieval mystery plays focused on the representation of Bible stories in churches as tableaux with accompanying antiphonal song. They told of subjects such as the Creation, Adam and Eve, the murder of Abel, and the Last Judgement.2 Often they were performed together in cycles which could last for days.3 The name derives from mystery used in its sense of miracle,4 but an occasionally quoted derivation is from ministerium, meaning craft, and so the 'mysteries' or plays performed by the craft guilds. 
  
  Spanish mystery plays
  
  The Misteri d'Elx (in English, the Elx Mystery Play or Mystery Play of Elx) is a liturgical drama dating from the Middle Ages which has been enacted and celebrated every year without any known interruptions. Commemorating the Assumption of Mary, it is played on every 14 and 15 August in the Basilica de Santa María in the city of Elx (also known as Elche). The prohibition of theatrical plays in churches by the Council of Trent eventually threatened to interrupt the yearly performance of the Misteri, but in 1632 Pope Urban VIII issued a special permit for its continuation. In 2001, UNESCO declared it one of the Masterpieces of the Oral and Intangible Heritage of Humanity. - Mystery play (Wikipedia)


In the Middle Ages many story and legends abound about how plants and to a lesser degree animals got their names associated with various biblical events, saints or religious truths of one sort or another:

Blessing Basil Leaf in Honour of the Holy Cross

St. George's mushroom