Is a believer afflicted with trials, or is what befalls him of tribulation a sign of Allah's wrath, and how can one distinguish between the two?

Patience in the face of tribulation leads to immense reward. It is not possible to distinguish whether a tribulation is a punishment for sin or a trial to elevate one's ranks, because this knowledge belongs to the unseen. However, if a servant is negligent, he should know that the tribulation is due to his sin, and if he is obedient, he should hope for reward for the calamity.