Working for Allah is strange business. To say the least, it is a one-way traffic.
Those who say they work for Allah give everything and receive nothing in return. Except, of course, from their God – provided their intentions are pure and their actions are good and right.
Time and again, In Ajriya Illa 'Alallah, is how the Qur’an puts it.
“My reward will come from God, and from no one else,” is how we can paraphrase that Aayat.
And again the Qur’an says, repeatedly, in Surah Ash-Shu’araa’:
Wa Maa As-alukum 'Alaihi Min Ajr.
“I ask you not for any reward or recompense.”
In other words, working for Allah, and inviting people to come to Allah, is hard work. Only the most privileged ones are chosen for it.
And their numbers are always very small.