He was down and out, the Catholics took him in, and before he knew it, he had faith. So it was gratitude that decided the issue, most likely. Human decisions are terribly simple.
The quote reflects the transformative power of gratitude and faith in a person's life. It illustrates how someone's dire circumstances can lead them to find support in unexpected places, such as a religious community. The character's experience of being 'down and out' signifies a low point where help from others can spark a new belief system and perspective.
Kundera suggests that the complexity of human decisions often boils down to simple emotions like gratitude. This emphasizes that, despite the intricate nature of our choices, the underlying feelings can guide us profoundly in our journey, impacting our lives in significant ways.