Is the justification for the difference in salary between employees—Muslims and Christians—despite the variation in tasks and experiences, covered by the concept of "and He provides to whom He wills without reckoning," and must one submit to this reality?

Sustenance, its expansion, and its constriction are from Allah Almighty by His decree and destiny. No human being can change their sustenance. However, Allah dispenses sustenance to His servants according to the means He has ordained. A Muslim must fear Allah and strive to acquire lawful sustenance, avoid the unlawful, and be content with what Allah has apportioned for them. Furthermore, not performing work as required is impermissible, and a Muslim must repent from such acts.