What are the causes of spiritual lethargy and its cure?

The questioner : The issue of spiritual lethargy, its causes, and its cure?

The Shaykh : Yes, a person cannot maintain a single level of intensity. Even the Companions said: . A person cannot maintain a single level of intensity, but he should preserve the soundness of his heart. If the heart is sound, the entire body is sound. He should refrain from delving into what does not concern him, refrain from disputes that yield no benefit, refrain from the partisanship that divided the Ummah, and turn to Allah (Mighty and Majestic). For this reason, you see the common person is better in his creed and sincerity than many students of knowledge who have no concern other than taking and giving, gossip, and what so-and-so says, what so-and-so says, and what is said in such-and-such a book. This is what wastes the servant, diverts his heart from Allah (Mighty and Majestic), and leaves him with no concern other than gossip. My advice to every person is to turn to Allah (Mighty and Majestic) and leave people and their disputes; this is better.