"A young man who wishes to remain a sound atheist cannot be too careful of his reading"

This quote by C. S. Lewis suggests that a boy who wants to remain an atheist must be mindful of what he reads. Lewis suggests that checking out certain products could lead to a change in beliefs, and that a young man should be aware of this. He is suggesting that reading materials that are spiritual in nature might result in a modification in beliefs, which a young man should be aware of this. He is recommending that a boy ought to be careful to read materials that remain in line with his beliefs, and not to read materials that could potentially lead to a change in beliefs. This quote is a tip to be mindful of what we read, and to be aware of the prospective repercussions of checking out specific products. It is a suggestion to be aware of our own beliefs and to be cautious to not let our beliefs be swayed by what we check out.