Understanding 'Illuminate' in Context

In a reflective essay about the transformative power of literature, the author writes:

“Books possess a unique ability to illuminate the depths of human experience, allowing readers to navigate the intricate landscapes of their own lives. This characteristic often evokes a camaraderie among those who read the same texts, fostering discussions that are both profound and enlightening. However, there are instances where literature can also introduce disquieting thoughts, as it challenges the reader's perceptions and compels them to confront uncomfortable truths.”

What does the word illuminate most closely mean in the context of the passage?