Rage, to me there are two sides to this
Inwardly, I like to know. I like to sortof make my mind up: Could there be a god or a power or something, to me, in my mind, in my own personal secret? I decide what I know. I weigh the options, and settle on what I consider most likely.
So, if you argue about what I know, for me, then I will be quite stubborn. I know what I know.
If we, however, talk more "outwardly", we discuss life and philosophy in general, I'm not gonna go out of my way to crash what you believe to be true, and I always try to remember that agnostics, or even moderate religious folk are a 'good compromise', to put it that way.
But for me, privately, I do insist/pretend to know my own truth.