That's true. As perhaps you're aware, as indicated by your 100-year time-frame, what actually happened was that Edwin Hubble debunked their theory of an eternal universe when he discovered that our universe had an actual beginning, the Big Bang--or better, the Cosmic Creation Event.
There's an interesting dichotomy among scientists. Astronomers, who look back in time, are almost universally deists if not also theists, because they now realize that the universe's beginning required a transcendant Beginner. Biologists, who look at current and recent times, are mainly atheistic or agnostic, because they are studying that part of creation since God stopped creating new species (we're still in the Seventh Day), so they observe no direct current evidence of creation and draw the wrong conclusion.
I suggest that the concept of a God is deeper than that. That there some fundamental “force” or “connection” that gives us the concept of a God.
His name is the Holy Spirit, Who witnesses to each of us in a way best suited to us individually. God has implanted an eternal spirit in each of us, which is what distinguishes us from all other animals, and one of its components is our conscience. CS Lewis wrote eloquently and accessibly about this in his classic, Mere Christianity. Additionally, creation testifies for itself about God:
"...what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that men are without excuse." (Romans 1:19b-20)
Bottom line: As we stumble clumsily along trying to understand a nature through science and the scientific process, we should be humbled by the fact that there is so little that we know and understand.
We should certainly be humble, primarily about the fact that we do not measure up to God's standard of perfection. Although we do have much more to learn about our universe, we do already know enough about God and how to please Him (through faith--see my tagline), because He has made it His mission to inform us, generally as above and specifically through His Word and His Son.
Adding to what you said below...
Maybe they are atheistic because their world is limited to a petri dish and the semi-microscopic level. They see the biological processes but miss the underlying abstraction of the very, very small and very, very large.
Maybe like the classical and modern sciences of the very large and very small, there is a major evolution of the biological sciences right around the corner. Maybe concrete proof of that our existence extends beyond the physical world and a redefinition of existence.