Nothing is permanent in this world. Galaxies dies, starts dies and the universe will not remain for eternity. The bigger starts, larger than the sun die in nova and supernova explosions when their fuel ends. It is estimated that the whole life of the sun is 10 billion years. It has spent half of its life. When it will burn all of its hydrogen, it will start fusion of helium. Ultimately, it will become a red giant and engulf planets one by one. Life from the earth will have been ended much earlier than that. So, the planet earth has maximum five billion years to survive. But, it can end much earlier than that time. Collision with a gigantic asteroid can destroy it anytime. Also, our whole solar system can be destroyed by black holes. Even the whole universe will ultimately collapse in a single point and die. This may be the restarting of the whole universe again.
So, everything has its maximum life. After a definite age everything dies. Planet earth will also follow this trait and eventually destroyed.