The prophet Mohammad (peace be upon him) a messenger of Almighty Allah. Who is the merciful for all mankind not only for Muslim.
Once, the prophet Mohammad saw an old women, she had no one to beside her to help her and she was trying to lift some luggage up on to her camel to go home. And when prophet Mohammad saw her, he immediately reached to help her.
The prophet did not asked her about her religion and what she followed and where she came from. This is not important to the Muslim.
So watch this video about prophet Mohammad (Peace Be upon him).