Kinda depends on what you mean when you talk/think about "God"- your personal teleology. If you picture a sort of Cosmic Big Guy who sits in front of a control panel and decides, 'Let's see, I caught Johnny smoking, so today he will fall out of a tree and break his arm. Susie helps her mother so she gets an A in spelling. Farmer Jones over there? Didn't see him in church last Sunday, so I think maybe a hail storm...' then you gotta take "The Devil" right along with him- they're a set, created a coupla thousand years ago by a committee of men. who 'knew' the earth was flat.  Edit: I got that part wrong. Thanks, Paystar!

If, however, you take more of a Deist slant to your metaphysics, then you certainly are valid in rejecting the 'God is in heaven somewhere up in the sky, where Grandma and Grandpa and my pet dog are waiting for me, streets of gold, etc. and Satan is in hell, somewhere under our feet in a lake of fire' notion. It's pretty obvious to me that Satan and Hell were dreamt up by the marketing subcommittee to scare the simple folk into showing up and supporting ($$) the church.

I was brought up in The Church (Missouri Synod Lutheran) and even stayed with it a few years after I left home. I rather liked the time to sit and reflect on things. Maybe I sat and reflected a bit too much, because finally I just couldn't get beyond thinking, 'This all sounds an awful lot like another guy- a guy who wears boots instead of sandals, a red suit instead of robes, but still gives you something if you believe and try your best to be good. And that guy doesn't seem to need some sort of opposite/antagonist to validate his goodness.'