If I was God...
I would make pretentious people smell like farts all week, just to embarrass them.
I would make politicians' noses elongate when they told lies.
I would strike with lightening and kill anyone who caused violence to vulnerable creatures- children, small animals, etc.
I would follow round all those who deem themselves to be saints and prophets and I would burn bushes just for them while filling their heads with my voice. I would mainly shout random things, like "where's the cheese, Sonny", or "don't eat that bagel, Mabel", but occasionally I would furnish them with great insight. This would depend soley on their choise of footwear.
I would persuade the richest to convert, suddenly, to my call, and they would become philanthropists...
I would give people a few millenia's worth of miracles in a short space of time- I would drag the arora borealis lights down to Blackpool, for instance, and magic away the Eiifel tower for a week or two, only to make it reappear in somewhere like the Pacific Atoll, paint the Taj Mahal bright green, etc.
After I had enjoyed myself with amusements such as these, I'd then get onto the business of being God.
Firstly, I would fix the hole in the ozone layer and lower the temperature inside a little.
Then I would make disappear all weapons of mass destruction and all bombs and guns. I would then ensure nobody remembered what guns or bombs where, and wipe all knowledge of them from the minds of man.
I would raise the IQ of the worlds population by an average of ten points. Those with an 1Q of less than 100 I would raise by 50.
All of the above would happen over the course of a month, to give the media time to report on the global changes and stir up the people.
Then I would broadcast myself on all TV's and radios at once, to introduce myself to the people, and I would give them some advice to follow and perform some more miracles to impress them and secure their alleigiance.
I would get rid of all nuclear power and convert everything to green technologies. I would then make sure all people had money, suddenly, and their larders would be full of delightful fruits and vegetables and grains.
Then I would appear on earth somewhere and live like the Wizard of Oz inside a fabulous emerald city and pilgrims would spend many years travelling to find me within my secret location. When they did, we would drink beer, I would then bless them, give them a really great vision to take back home to the kids, and send them home satisfied. In a spaceship.