One thing I never understood: If God exists, why isn't this a lot more obvious? I want to believe there's something out there (I identify as agnostic), but why do we need such complex logical arguments to justify it if he's out there?
Because it is already obvious. God has made himself manifest in the world not just generally in creation, but specifically in one person: Jesus Christ.
Leaving aside the problem of God's holiness, if God personally appeared to everyone to tell them "I exist!" there is no reason to believe that it wouldn't be explained away in similar ways to the miraculous signs of Jesus (which eyewitnesses themselves often rejected.)
