First off, we're not talking leprechauns or unicorns. They are legends and are vividly described, at that. And also said to be visual entities, or seen. God, to most, isn't claimed to be something we can see.
And as to proving God, look all around you. If you believe it all evolved from simpler life forms, then think back to when it was simplest. Take life today, if it had to represent a number, let's call it 1,234. And at 600 - prehistoric age of dinosaurs, 100 - single celled organisms, etc. So what's at 0? Is it creation. And what made that period of 1. Or .11111....and so on, for that matter. It all comes down to one simple organism, right? And what made that organism into matter in which we can observe? Fact is, we don't know. Atheists call it ?. Some religious call it God. What and where is the big deal in that? True, it may seem wacky when people (prophets) say they have made contact with the creator, but can you honestly say, these people (I'm speaking of the prophets of the Abrahamic God) are here to spread hate? So 0, for example, is it a number or nothing? So even if 0 is not a number, it is something. It makes a number a number. It tells something that it is not nothing. So prove 0 doesn't exist. You may not see it but it can be represented. 0 is the mother of all numbers as God is the father of all life and time. As I said before, if time is represented in a linear sequence, it all boils down to 0 hour. And what made that first second/millisecond time? Something is the father or birther of time and it all started at 0. 0, for the unimaginable, the unintelligible, or the mindless people out there, may not mean anything. But to the wise man, he knows that without nothing, a negative, absence, there will not be something, it will always be nothing. 0-1=0. Negative isn't always negative in the emotional perspective, it exists to let us know when something is, or when something is right, or when something is good, as a comparative value. I could go on, but if you're smart enough, you can take it to more levels if you know what I'm talking about. That is one of my many arguments. And the last time I will go over it (maybe, lol). Everyone always asks the same "god exists?" questions.