Show up in front of me, and prove it itself. Defining "God" to be merely any omnipotent being, he'd need to somehow demonstrate his omnipotence to me. How is another matter, but some kind of time shifting would be sufficient. Anything else I'd probably rationalise.
And for me to deem it worthy of worship, without coercion? Probably not going to happen, if the world continues business as normal then I wouldn't deem it worthy of worship. I'd hesitate to even deem it worthy of respect. For my respect, it'd have to sort the shit we're in out. I leave that open because it'd take more than a single post to list what shit in particular I'm talking about. It'd have to cure me of my insomnia and my haemmoroids. For my worship... it'd have to telepathically give me a high beyond anything drugs or meditation is capable of. Hey, I'm hedonistic.