Everything material is temporary

Bhagavad Gita Chapter 2 Text 16
Excerpt from Srila Bhaktivedanta Narayana Maharajas purport "Of the temporary, such as winter or summer, there is no permanent existence, and of the eternal, such as the soul, there is no destruction. Those who know the Truth have reached this conclusion by deliberating on what is temporary and what is eternal."

Everything is temporary O son of Kuntī, the non permanent appearance of happiness and distress, and their disappearance in due course, are like the appearance and disappearance of winter and summer seasons. They arise from sense perception, O scion of Bharata, and one must learn to tolerate them without being disturbed. Bhagavad Gita Chapter 2 Text 14 by Bhaktivedanta Swami During worry, we let our thoughts take us away from our circumstances to a problem – real or imagined. And letting our thoughts take us away from our circumstances is the essential ability required for meditation. Thus proper Krishna meditation can replace worry and anxiety.