What is the solution for laziness in performing acts of obedience and worship, and for losing the joy of them after having been steadfast in their performance?

Lethargy and relapse are caused by the domination of Satan, the prevalence of whims and desires, the soul that incites to evil, or a hidden sin. The path to rectification begins with getting rid of all sins and sincere repentance, then striving against the self to return to acts of obedience and increasing good deeds with patience and perseverance, while frequently supplicating and remembering Allah the Almighty. It is also necessary to associate with good people, attend gatherings of knowledge and remembrance, and seek out causes that soften the heart, such as visiting the sick, visiting graves, and contemplating the Hereafter.