Let's say that science proves that God exists

[orogenicman]

The only place we know where evolution took place (assuming it works as its supposed to) is on planet earth, with abundant water, stable seasons and just the right distance from the sun. Not to mention a core that gives off a magnetic field that shields us from the harmful effects of the sun. From what can be ascertained, not only do very specific planetary conditions need to be satisfied but also universal conditions such as the right strength of gravity to form planets, form stars, galaxies and so forth. If life were tunable to the conditions as you suggest, we should see life that adapted to conditions on the moon or mars but so far no evidence of that.

Yes, the only place we know so far where evolution has taken place is on Earth. But the conditions in which life occurs are far more varied than we previously assumed. We have found organisms thriving in geothermal springs that would scald most life. We have found organisms that can survive being nearly completely dessicated for long periods of time. We have even found organisms that can survive for a time in hard radiation and the vacuum of space. Even so, the vast bulk of life on Earth does live within a narrow range of parameters. And they do because they have evolved to survive in those parameters. So yes, life has evolved, has been tuned via natural selection to survive based on a range of conditions, as far as we know (and we do know quite a lot about this). But life on this planet didn't start out livng within the parameters that most life on the planet today thrives. The earliest days of the Earth when life first evolved was completely different from what it is today. And like organisms do today, ancient organisms interacted with their environments in ways that substantially altered those environments gradually over long periods of time. And evolved as those environments changed. We change our environment to suit our needs. Other organisms do the same.

But the vast bulk of the universe does not contain the requisite conditions for life as we know it (i.e., the conditions that exist here on Earth) to become established, to evolve, and to thrive. In fact, and this really is the inescapable part that appears to elude you, the bulk of the universe is utterly and irrefutably unlivable. Another point to consider is that the universe may be inherently unstable (http://www.bbc.co.uk/news/science-environment-21499765#). So the anthropomorphic notion that the universe is finely tuned for life is simply mistaken.

I assume they don't hold water with folks who are arguing in favor of atheism and are advocates of atheism, they do hold water with me.

I'm happy for you. But if you are trying to post a winable argument on an atheist forum, I am afraid you are going to have to convince more people than just yourself.