That is the very question that should lead you to God. There are many clues to His existence if you wish to examine. Has the universe been here forever? No. Physics and laws of thermodynamics tell us emphatically no. The universe had to be created. and it was. By Gods Word. His Word has power and it is this power that created you and I. Einsteins Relativity Theory explains the relationship between energy and mass. They are interchangeable under the right conditions. Do not despair over your meager mayfly life span. God promises more and better. Much better.
You got it Bob!