Pastor Rick Warren’s book by that name sold 30 million copies. I understand the book is about devoting ones’s life to the God of the universe. That is a “purpose”.
Religions teach that there is some great purpose for each of us in gods. It is clear, to me at least, the universe does not care about our “purpose”. The sun will burn out and that’s the end of us. The universe has never heard or nor cares about any of us or the thousands of gods humans have worshiped.
So should we feel lost and unhappy about this? No, there is a purpose to life. It is to take care of ourselves and of those around us.
A purpose is also the figure out how to make the planet a place that will support life as long as possible. Further generations are a purpose for us. We should do whatever we can for generations to follow.
We are debating how to carry out that purpose. While we can do this believing or not believing in gods, we cannot live a purpose driven life without trying to learn about the science surrounding survival of the earth. Ridiculing science, which is done by many, is the opposite and is living without purpose.
Some three dozen times here I have been warned I will pay some kind on consequence for not believing in the existence of gods. To me, those who spend their lives preoccupied with something other than caring about mother earth and the people who live on it are lives wasted.