We observe animals, plants and insects beginning life. We see their lives come to an end. We speak of the birth and the death of civilizations, of storms, volcanoes and comets. We are accustomed to seeing things get old. Clothing and furniture wear out.
Automobiles fall apart.
Our bodies become wrinkled and slow. To mortals, everything has a beginning, a period of usefulness and an end. We mark this progression of events on our clocks and calendars. To us, what is measurable by hours, days and years seems to have real significance. So when we hear that God is eternal, that he always has been and always will be, our minds may balk.