Imam Mehdi is here???

you are right:

we should
(1) accept the difference
(2) try to find the common grounds

and there is another thing we should not forget

(3) we should try to understand what the other sect is saying.

most of the people in other sect even dont understand what shias are saying.
they think that shia give importance to "the linage". actually its not.

Shias give importance to "Naas".

example: Shias accept him as an imam; not because of "he is son of". He is imam because there is a Naas for him. that is it.