Have mercy love pity compassion on mankind for their success in life after death:Core Requirement of Daee,Dawah Manhaj/Nahaj and for Dawah and Tabligh o Islah worker in different field

It is related in the hadith,"Whosoever does not show mercy, will not be shown mercy. Have mercy upon those on earth and the one in the heaven will show mercy on you." 

It is a pity that people have restricted this mercy to those who are hungry, thirsty and naked, and have no pity on those who are deprived of Deen. It is as if they consider the loss of material things to be harm but do not consider a loss of spiritual values to be a loss at all. Therefore, why should the one in the heaven have pity upon us when we do not take pity on the ruined spiritual conditions of Muslims.

The foundation of our tabligh is based upon this pity. Therefore, this work should only be done with compassion and feelings of mercy. If a muballigh is doing this work because he feels sorry for the sad state of his fellow-men then he is certainly fulfilling his duty with compassion and sympathy. If he does not have this disposition but has another intention, then he will be involved in pride and self-elation from which no benefit can be expected. The one who will bear this hadith in mind while doing the work will have sincerity, see his own faults and although his gaze may fall onto the faults of others, he will also see the good Islamic qualities in them. Such a person will not defend his nafs (lower self) but will complain against it. The crux of this tabligh is not to encourage the self but to complain of the self.
The Discourses of Maulana Ilyas rh