Imam Ja’far As-Sadiq (as) says that a Mu’min doesn’t spend forty days when a new difficulty does not confront him. In fact, he is not a Mu’min who is free of all worldly difficulties!
The Imam (as) said: A person invited the Prophet (S) over a meal. When the fare was laid in the courtyard of the house, the Prophet (S) looked towards the wall of the house. He noticed a pigeon has laid an egg that was resting on the top of the wall. And thus was saved. He told to the host, “Your pigeon has laid an egg that is lying safely on the top of the wall!” The man said, “O Allah’s Prophet (S)! What is there to be surprised about that? I swear by the Creator, Allah, that in my entire life I have not suffered any loss!”
When the Prophet (S) heard this, he got up and said, “I cannot share a meal with a person who has never suffered any loss whatsoever during his entire life! I do this because you have no contact with Allah and you don’t possess any quality. A Mu’min, even if he is comparatively comfortable in the world, will be in difficulty when compared with the comforts he would enjoy in the Hereafter! Even if a Mu’min is given the entire world, the status that awaits him in the Hereafter is far superior to what is available to him in this life! In comparison this world is like the Hell for a Mu’min. Similarly if an infidel is involved in all the worldly hardships, his life here will be like living in the heaven when compared with the hardships that he would bear in the Hereafter.”
Reference :Ain-Al Hayat, The Essence of Life