While Intelligent Design skeptics may claim there is no evidence of God, the actual scientific evidence for God's existence is overwhelming, scientifically answering the question, "does God exist?".
In science there is a Law of Physics called the 1st Law of Thermodynamics. Within it is a Conservation of Energy Law that states, as a key principle that all energy in a closed system must be conserved. Okay, fancy language, but what does that mean? It means that while energy can convert into matter (physical “stuff”), and matter into energy, however much total “stuff” there is (matter and energy), there can never be an increase in that total amount or a decrease in that total amount. So however much total “stuff” there is in the universe, (matter and energy combined), there can never have been more and never have been less. All it can do is convert to different forms, like matter to energy or energy to matter, but the total amount of all of it has to remain the same.
The “closed system” is a scientific term that refers to a system or an “area” that has no outside influence, like the universe. Now, as believers we know, of course, that God does influence the universe, so many believers would consider the universe an “open system”, (one that does get outside influence), but for the atheist who says there is no God, the universe is all there is, so from their perspective and for the sake of conventional science, the universe would get no outside influence and would therefore be considered a “closed system”.
Back to the 1st Law of Thermodynamics. If it states that you can never have an increase or decrease of energy/matter, which means that matter/energy can not be created from nothingness, how did we get all the matter and energy in the universe? If science is all there is and there is no God, then the 1st Law of Thermodynamics reigns supreme and therefore it would be impossible to have matter and energy in existence right now. Simply put, when you open your eyes and see matter and experience energy, what you see is impossible according to the known Laws of science if, in fact, there is no God. Therefore, science itself says there must be a God.
Plain and simple, matter/energy can not come into existence. It is scientifically impossible, yet here we see everything around us, so how can that be? There are really only 3 possibilities. Option A: Everything came into existence by itself anyway, without the help of God, (even though science has proven that impossible). Option B: Everything in the universe has always existed for all of eternity, (which, by the way is also scientifically impossible as explained in the Top Ten Proofs for God's Existence CD due to something called the 2nd Law of Thermodynamics), or Option C: There must be a God, a Being greater than science, who created the Laws of science and has the ability to disobey them. Not only is a belief in God the only logical conclusion to draw, it's the only one scientifically possible because remember, if there is no God, the first two options are scientifically impossible according to the actual Laws of Physics.
Believe it or not, a 5 year old child could be an atheistic scientist's worst nightmare by merely asking him “where did everything come from if God didn't make it?” What that child is actually asking in scientific terms is “how do we have a violation of the 1st Law of Thermodynamics by the creation of energy and matter in the closed system of the universe if there is no Creator capable of doing that?”
Many times people who do not believe there is evidence of God have claimed that a faith in God is only a matter of faith and that it can not be proven scientifically. They say "does God exist ?....if so, prove it to me". When confronted with this, we must fully understand what it means to “prove” something. The fact is that none of us were there when the universe came into being, so technically, none of us can “prove” what happened. We can't “prove” God did it and the atheists can't “prove” everything came into being on it's own, so what we have to do is examine the evidence based on science to determine the most plausible explanation. For example, if I see a beautiful sand castle on the beach with intricate design, but no one there along with it, I can not “prove” someone made it, just as someone else can not “prove” the sand castle made itself from the wind, waves and sand randomly interacting with one another, so we have to determine what logic and reason tell us is the most plausible explanation, based on scientific evidence and examination. You can get over an hour of scientific, mathemetical and logical evidence for God in the <Top Ten Proofs for God's Existence.
This is just one simple example of scientific evidence for God's existence out of many that can help you defend the faith with evidence of God based on science and logic, not just faith.