C.S. Lewis's "Screwtape Letters" warns against relying on scientific understanding to defend Christianity. He argues that true science, which deals with tangible realities, might lead individuals to contemplate abstract concepts that transcend mere physical observation. This suggests a caution against misusing scientific reasoning to validate faith, as it can distract from spiritual truths.

Ultimately, Lewis emphasizes that faith in Christianity should not be contingent upon scientific validation. Instead, believers might need to embrace the mysteries of their faith without trying to ground them solely in empirical evidence, acknowledging that some aspects of existence are beyond human perception and understanding.