Why is life on Earth considered more valuable than a life in heaven for someone seeking to overcome the fear of death?

Chapter 37 argues that the earth-world is of profound importance, even more so than heaven, for attaining liberation from fear. While heavens like Indra's garden may offer sensual pleasures, they are temporary; one falls from heaven once their accumulated merit is exhausted. The earth-world, in contrast, is described as the unique place for acquiring the "science of the oneness of Brahman and the Self," which is the ultimate means to liberation. As stated in Chapter 37, even though life on earth is fleeting, a person who "offers every action performed in a moment to God attains the place of fearlessness." This makes the earthly realm the critical ground for achieving permanent freedom from the cycle of birth and death.