Most of the observable universe is made of hydrogen. Stars like our Sun are fueled through the fusion of this hydrogen into heavier elements like helium and carbon. Huge amounts of energy are released during the fusion process, and we feel and see some of this energy as light here on Earth. Stars that are much more massive than the Sun are able to achieve temperatures at their core in the billions of degrees. These high temperatures allow them to continue fusing elements all the way up to iron. Elements beyond iron cannot be formed through fusion since the fusion of iron actually requires energy to occur. Elements beyond iron are formed when one of these incredibly high mass stars explode in what is called a supernova. The explosive power of the supernova gives us the heavier elements, and enriches the interstellar medium for the next generation of stars.
Realize that God who created the stars in this way is the same God who loves you today. When I look at your heavens, the work of your fingers, the moon and the stars, which you have set in place, what is man that you are mindful of him, and the son of man that you care for him? – Psalm 8:3-4