Maybe you are:

"I'm" asking to show.....Them as "Us"......is the wrong direction to point your request you are requesting of.

I'm can not mediate the imparting of belief unto any by I'm's request.

Instead since you are a and the "I'm"......limit your request to what you want for and from your own self and don't include any "us's".

You could ask for any sign and this of course being left up to the granter could be many many things ...like:
Leprosy
Blindness
Muteness
A fissure opening in the earth swallowing you up into it as it closes up on you.
Lightening strike you.

Baldness would be a good one to ask for...there was a man one time who said if there was a God then I am bald and will not even have a hair on my head.

We nicknamed Him Onion Head.......got struck dead by lightening in a boat with two other men years later..

We then referred to him as Fried Onion Head we even made a camp joke about him kind of a poem to tell the story of the stripped naked Onion Head....all round and bumpy not a hair left.

It ended this way...

Poor Ole Onion Head changed his mind and still struck dead
Fried him good as a sign unto us all
Be careful what you say or the fire might fall
Right back on your head after you have forgotten
The tempting takes time to meet the end of its line
When its returned to sender like an unpaid fine...:(

Some times I feel like a nut sometimes I don't...
yet
All minds are like nut meats...and all their shells are hard.
Cracking into that mind takes time realizing it don't.

Have a good day and take it easy something good this way comes....if you are looking for it...:)