What are the reasons for success in calling to Allah and getting rid of the whispers of Satan such as despair, cowardice, and laziness?

Two remedies are proposed to combat the despair, cowardice, and laziness that confront preachers: The first is to remember the immense reward from Allah and the verses that give glad tidings to preachers. The second is to read the biographies of preachers, and especially that of their master, Muhammad, peace and blessings be upon him, in order to emulate their high aspirations and patience. For a true Muslim does not allow any excuse to deter him from supporting Allah's religion.