How can a Muslim differentiate between a straitening of provision as a trial from God, and a straitening of provision as part of the hard life promised to those who turn away from the remembrance of God, or as a punishment for a sin committed?

The believer who is steadfast in obedience considers a constricted livelihood a trial from Allah, for which he will be greatly rewarded. As for the disobedient one, he may be deprived of provision due to his sins, or it may be expanded for him as a gradual enticement, after which he will be punished. So, the believer may be tested with a lack of material possessions but remains happy, whereas the wicked person may be punished with a lack of them or experience an increase as a gradual enticement, and suffer from anxiety.