Assalamu Alaikum Dear Brothers and Sisters,
Scholars indicate that Iman is not constant. Our level of faith increases with obedience to Allah and decreases with disobedience. As believers, we should pay attention to our level of Iman, being aware of when it increases and decreases and striving to be in a state of elevated Iman as much as possible.
The Prophet (peace be upon him) stated that: "Every heart has a cloud covering it, with the similitude of a cloud covering a shining moon. It suddenly becomes dark when the cloud covers, but its brightness returns once the cloud has passed." [Al-Hilyah]
In this hadith, the Prophet presents an analogy. Our hearts are likened to the moon; just as the moon is sometimes covered by clouds that conceal its light, the heart is sometimes covered by clouds of sin that cover its light. At other times, the clouds go away, and the light shines again in the heart. The light increases when we strive to engage in acts that will increase our Iman.
The Prophet explained: "Faith wears out in the heart of any of you just as clothes wear out, so ask Allah to renew the faith in your hearts." [Al-Hakim]