"Time" not a dimension.

[lilphil1989]

I mean... if we have local times, can't it be a global time too (which should be = the order of events).
If all the universe exists "at the same time", doesn't that imply a global time?

Having an order of events is not the same as having a global time.
A concrete example: An observer on Earth sees events in the same order as observer sitting on a GPS satellite. However, the Earth observer sees the clock on the satellite running at a different speed to his wristwatch due to gravitational time dilation (and the GPS system has an algorithm built in which corrects for this effect).
So whilst events are in a well-defined order, there is no global time.

And if we have an order of events (i.e. a global time), then two events may happen at the same time (according to this global time). But according to the local times (i.e. here 1 second = there 1 year, and stuff like that) they may happen one after another. Isn't this a paradox?

Actually that's exactly what happens. It's called the relativity of simultaneity. If I see two events as simultaneous, then someone in motion with respect to me will not. Of course, for it to be a noticable effect, the speed has to be large. Indeed, the whole reason we were satisfied with the idea of absolute simultaneity for so long is that we live at very low speeds!

it's regarding that thing with the omnipresent god I tried to explain, you know, to try to imagine a global time.

You may as well try to imagine invisible pink unicorns . Global time is not compatible with relativity.