Modern science really doesn't say that, but they wish they could.
Order never arises out of chaos.
If I were to take my watch, smash it against the wall so that it falls into hundreds of little pieces; how long would I have to stand over that mess of little watch pieces before they all came together and made a perfectly working watch again?
Would it ever happen?
But that is what the Big Bang "theory" teaches.
Out of this chaotic bang we suddenly have perfectly ordered solar systems, galaxies, etc., all moving in precise positions. It is impossible that a chaotic bang would produce that. How did the earth get so green with a perfect atmosphere for life to exist on it--the exact distance away from the sun to be the right temperature, rotating at the right speed, and revolves around the sun at just the right speed. Everything was "created" just perfect. Order doesn't come from chaos.
Well, the scriptures repeatedly say God stretched out the heavens:
Isa 42:5 Thus saith God the LORD,
he that created the heavens, and stretched them out; he that spread forth the earth, and that which cometh out of it; he that giveth breath unto the people upon it, and spirit to them that walk therein:
Isa 45:12 I have made the earth, and created man upon it: I, even my hands,
have stretched out the heavens, and all their host have I commanded.
Jer 10:12 He hath made the earth by his power, he hath established the world by his wisdom,
and hath stretched out the heavens by his discretion.
Now, this doesn't say the universe exploded, it says God stretched out the heavens. This is similar to the Big Bang, you often see it represented as an explosion, but it is more accurate to say science believes the universe "expanded" from a single point. This agrees with the scriptures.
Many physicists and astronomers originally opposed the Big Bang theory because it seemed to agree with the Bible. Fact.
I am not endorsing the Big Bang theory, except that the scriptures do teach that God stretched out the heavens. Of course there are many differences, the Bible teaches that the Earth was created before the Sun, Moon, or stars. So there are many differences.
But the expansion of the universe is biblical.