Professor Ansarian:
If the believers and the pious people don,t value one another, the others wont do so. If we want to judge a Muslim, we must judge him in comparison with the Pagan, idolatry, Bahaiee and Wahhabi. Then, along with his defects and faults, if we notice any kindness and love of him toward Imam Ali peace be upon him, then we could possibly treat him in a rather kind way. If the believers act kindly with one another, the others may be attracted to the religion. For the bad ones to become good, the good people should become better.
source : erfan.ir