What is a person's sin if they are afflicted with the coronavirus or lose their job because of it, and how can one deal with Allah's divine decree (Qadaa' and Qadar) in such circumstances?

Everything that befalls a servant is by the decree of Allah, according to His wisdom and mercy, and Allah is not questioned about what He does. The servant must submit to Allah's judgment when their intellect is unable to grasp divine wisdom. The true calamity is in one's religion; all other calamities elevate ranks and expiate sins. Affliction is not a sign of Allah's wrath; rather, it may be a sign of His love. Allah may afflict a servant whom He loves, for well-being can be a gradual enticement [towards sin], while affliction can be a means of elevation and honor.