The real objective of our practice is liberation, not rebirth in the higher realms. As such, we need to establish a path to liberation, with the primary requisite being renunciation. All practices that lead to liberation are based on renunciation. Renunciation is extremely important since we cannot progress to methods in subsequent stages without it. The purpose of seeing all contaminated things as suffering is to give rise to a resolution of complete renunciation.
~Depicted from THE FOUR SEALS OF DHARMA - All Contaminated Things are Unsatisfactory