Why is the concept of impermanence most sacred? By reflecting on continuous impermanence, we develop the motivation to practice. When our practice becomes lax, just thinking about impermanence — in life and in all worldly things — generates a strong desire to practice. If we practice momentary impermanence, it will be the basis for realization of no-self. This is because what is perceived to be “I” cannot exist when change is happening moment to moment. The realization of emptiness and no-self will come after a period of practice. Therefore, we must practice impermanence, and with practice, attain progress.
~ Depicted from THE FOUR SEALS OF DHARMA : All Composite Phenomena are Impermanence