Considering the importance that gods play in people's lives, why is the bar so low when we're talking about evidence for them?
I can't count the number of times that I've seen a theist respond to an atheist with some version of "yeah? Well, you don't know that God doesn't exist!" ... as if not being able to completely reject the possibility that gods might exist somewhere in some form justifies them devoting their lives to their God.
And the typical arguments for gods don't do much better. Think of the classical arguments for God: cosmological arguments, teleological arguments, ontological arguments, etc.: even if you set aside their logical problems, if they actually did what they set out to do, all they'd be really saying, effectively, is something like "if you take this set of factors into account, then you should conclude that there's a god out there somewhere."
But theistic-based religion is more than just the intellectual acceptance of the idea that a god exists; it's often full-blown devotion of a person's life to the existence of a god or gods and ideas that flow from it (e.g. living your life the way your god(s) want you to live it, or giving up significant time and money for worship of the god(s) and support of his/her/its/their church/clergy/etc.).
For many theists, their devotion to their god is akin to the devotion of a marriage. I don't know about other people, but if someone asks me to show that my wife exists, I can show them all sorts of evidence: pictures, stories of things she did, eyewitnesses who have also seen her, etc... I could even produce her herself and you could hear her say personally that yes, she really is my wife.
What I wouldn't do if I was asked to prove that my wife exists is make arguments like "well, sometimes when I wake up, the cats have already been fed, so it stands to reason someone lives in my house with me." And even that argument for the existence of my wife meets a higher bar than what theists typically shoot for when they try to prove their gods.
So what gives? Based on the level of discourse that I see around gods, even if I granted every one of the theists' arguments for the existence of their god(s), I'd only be at "okay - I can intellectually assent to the idea that God is possible"... or maybe with a really good argument get to "God is probable." I certainly wouldn't be anywhere near "I accept with my heart and soul that God exists, and that this is how he wants me to live my life, and I should give up a year of my life to go on a mission trip to convince other people that he exists."
Why the disparity? If the existence of gods is really an open question - and the level of discourse that I see suggests it is - then how is devotion to a theistic religion ever justified?