To be a Muslim is to preach Islam to everyone everywhere. This is a critical detail about Islam, and about being Muslim, that most Muslims seem to know nothing about.
But "preaching" means seeking to "convert" people from whatever they are right now to becoming Muslim. That is, you are not just asking people for a donation of a few dollars, but you are asking them for everything they own: their body; their mind; their wealth; and their very soul.
And their present world as well as their next world.
How hard do you think a bargain like that is going to go down?
And then on top of all that, you are supposed to do this using nothing but the nicest of means and methods. No lies, no deception, no cheating, no gimmicks, no mental or verbal sleights of hand, no false promises.
Just how do you do that? Are you surprised that Allah's Nabiy Yunus, Alaihis Salam, got discouraged after a while and left town?
So, those of us who are Working for Allah, those who are trying to preach Islam to both Muslims and non-Muslims, and all those who are trying to take the Qur'an to every home and heart that needs it, and which one does not, must hold on firmly to the rope of Allah and hang tight.
For them, better days are sure to come. If not today, then tomorrow. If not in this world, then absolutely, positively in the next world.
For, they are working to please Allah, and help Humanity, and not just to reap some quick worldly rewards.
And their goal is not just this world, but also the next world.