If I yelled: "Repent for the city of heaven is at hand" in the parking lot -- what would happen?

In my neighborhood nothing will happen, but............if you yell Hitler all hell will break loose!

What will happen to the two witnesses who will preach in Jerusalem during the end times? You would not be well received, just as Jesus wasn't during His Passion.

I would say, "John the Baptist said this thousands of years ago, and we're still waiting for that one!"

It's likely that someone would call the police on you.

I would quickly walk to my car, keeping an eye on you making sure you don't come towards me, and keep my eyes down. Then I would call 911 to report a physco. (no offense)

That depends on if you're in a parking garage or a parking lot.
If you're in a parking garage on any other level than the top one, you would hear an echo and know that God is on your side.

If you're in a parking lot or on the top floor of the garage, nothing would happen. And you would be sad. Mebbe even pout a little.

what would happen. no time or chance for repenting in the parking lot, all would have had their chance and it will be too late.

everyone will go into spiritual bodies and the great white throne judgement will began.

Dead-pan.

Freedom of speech does NOT give you the right to yell "Repent for the city of Heaven is at hand" in an empty parking lot.

I may be mixing this up with something else.

As long as you're not doing that to cause public disturbance, I don't see any problems with it. Personally, I admire that if you say that sincerely instead of trying to make fun of others' belief and religion.

People would throw coins at your feet and smile politely before instantly forgetting you.