What is the remedy for lack of success?

The greatest cause of a lack of success is committing sins and transgressions, as Allah Almighty said: ﴿And whatever strikes you of disaster - it is because of what your hands have earned, and He pardons much.﴾ [Ash-Shura:30] And ﴿Corruption has appeared on land and sea because of what the hands of people have earned, that He [Allah] may let them taste some of [the consequence of] what they have done that perhaps they will return [to righteousness].﴾ [Ar-Rum:41].

The cure is to avoid sins, observe obligations, increase in supererogatory acts, turn to Allah, repent and feel remorse, frequent gatherings of goodness and stay away from gatherings of evil, while taking the necessary means.