1. Atheists claim God does not exist. In this case it is clear science will not be able to measure anything as evidence for God's existence.
2. Christians claim that God is infinite. In this case we also have the situation that science will not be able to measure anything as evidence for God's existence.
Clearly science will find the exact same thing whether God exists or not. All we can conclude is that science is a poor method to discover God's existence. One will not find evidence of God using science any more than one will find evidence of an ocean by looking in the desert. If a person is really going to find out if God exists then they must find a better method than science.
This is why I suggest people go out and look for themselves. Study and participate in various religions and see if there is anything to them. Even if you still conclude that God does not exist, you will at least know that you used one of the better methods available.
"Where does God's free will come from" is similar to the question "Where does God come from". If God exists outside the boundary of time then God does not come from anywhere. God has always existed. Likewise God's free will has always existed. People do not exist outside the boundaries of time or space, so we ask about the cause of our free will (just like we look for a cause for any phenomena we observe). We cannot observe a cause, so commonly people assume that God is the cause.Strange! This is the first time I've heard of atheists arguing against free will.
Let me revise the Christian thing.
First of all there is a God with a free will. This one wants some company, creates (whether in six days like the Bible tells or with genetic manipulation which can't be distinguished from spontaneous evolution - I don't really care about the details here.) plants, animals and humans. Then he actively endows the humans with a spark from his free will.
So you start already with something with free will!
Why can't I start with something with a free will too? Why do I have to prove that you can create free will with nothing but chance and selection? You've got a much bigger problem than that! Where does that free will of God come from??
Conversely, atheists also cannot observe a cause for free will and instead assert that there is no free will. So that is why I hear atheists say there is no free will. (But then there is the issue that one cannot study the world around them without first assuming that one has a free and independent mind. So atheists have this contradiction to wrestle with.)
I'm sorry, but you'll have to do better than this. I asked for a non-cynical explanation. And it is clear that religion is universal. It occurs in every society, and even in societies where religion is outlawed people find a way to practice it illegally. I'm sure you can come up with a better explanation for religion if you actually examine the evidence.Why is religion universal? Because that's how humans are built. We always want explanations and causes for everything. We humans can't accept chance. We invent cause-effect relations and start believing in them. If you put manure on your field you'll get a better harvest. If you don't sacrifice a lamb to the Sun God, spring will not come back next year. If you change the direction of stirring while making dough, the bread will not rise.
You don't want to risk spring not coming back, so you won't experiment with "not sacrificing a lamb" this year. Until someone does.
The whole history is riddled with new ideas and beliefs coming up and old ones discarded or proven false.
Religion is not as universal as it used to be...