Ask people who describe their lives as purposeful how they got there, and very few of them tell the story the advice column promises. They didn't identify a calling and then pursue it. They tried things, noticed what opened up and what closed down, and built a direction out of those observations over a decade or two. Bill Burnett and Dave Evans, who teach life design at Stanford, put it bluntly: you can't think your way into a life, you can only build your way into one. Purpose, for most people, is less a thing you discover and more a thing you assemble and only recognize afterwards.
Which is why "find your passion" is such expensive advice. It sends you looking for an object that doesn't exist yet.
The books here reflect that, each from a different vantage point. Frankl built his framework for meaning while imprisoned in Nazi camps, which gives it a weight nothing else on this list can match. Tolle and Singer treat purpose as something that only becomes audible once the mental noise drops. Hesse spent a novel on what the search itself does to a person. García and Miralles went to Okinawa, interviewed people well past a hundred, and found that almost none of them described a grand calling: their sense of purpose came from small daily work and the people around them. These books don't agree with each other, and that disagreement is part of why they're worth reading together.
Some of these you read once and then return to mentally for years. Others work as a mirror whenever the question resurfaces, which it will. Start with the one whose description sounds like something you've already been circling.