In the lesson, it discusses the impact of the Protestant Reformation led by Martin Luther on the Catholic Church and the accessibility of the Bible to the general public. It explains how the invention of the printing press allowed more people to read the scriptures for themselves, reducing their reliance on clergy for interpretation. Luther challenged the Church’s practices, particularly the sale of indulgences, arguing that they contradicted biblical teachings. This movement sparked significant religious changes and allowed individuals to engage more directly with their faith.