We wish to know what things enable Eemaan to increase and what things make it decrease?
As far as the things that make Eemaan increase, then from them:
The first reason:
To know Allaah Ta’aala with His names and attributes. Indeed whenever a person’s knowledge of Allaah and His names and attributes increases, then his Eemaan increases without a doubt as a result. This is why you will find that the people of knowledge, those who know about the names and attributes of Allaah what others do not, you will find that they have stronger Eemaan than other than them from this perspective.
The second reason:
To Ponder over the Ayaat (signs) of Allaah, Both the universal and legislated signs. Indeed whenever a person ponders over the universal Ayaat, which is the creation; the heavens, the earth, humans, animals and other than that, will increase in Eemaan. Allaah Ta’aala says:
{And on the earth are signs for those who have Faith with certainty. And also in your own selves, Will you not then see?}
There are many verses that prove this. What I mean is, the verses that prove that if a person was to ponder and contemplate upon the universe, his Eemaan as a result will increase.
The third reason:
To practice a lot of good deeds, for whenever a person increases in practicing good deeds, his Eemaan will increase, whether these deeds are from the deeds of the tongue or actions of the body parts. For indeed Dhikr, (remembrance of Allaah) increases Eemaan in its amount (i.e. the number of times one makes Dhikr) as well as in the way it is practiced. Salaat and Sawm (fasting) as well, and Hajj increases Eemaan as in regards to the number of times it is practiced, as well as in regards to the way in which it is practiced.
As for the reasons why Eemaan decreases then it is the complete opposite of what has been mentioned.
So ignorance of the names and attributes of Allaah will make Eemaan decrease. Because if a person does not know the names and attributes of Allaah, then he lacks knowledge of them that [if he had] would in turn enable him to increase in Eemaan.
The second reason:
That one does not ponder over the universal and legislated Ayaat of Allaah. Indeed this causes Eemaan to decrease, or in the least will stop its growth .
Thirdly:
Falling into sins, for indeed the sin has a tremendous effect on the heart and on Eemaan!. This is why the messenger of Allaah صلى الله عليه و سلم said:
“The zaanee (adulterer) does not commit zinaa (adultery) while he is a believer at the time of the act.”
Fourthly:
Leaving off obedience (to Allaah and his Messenger), for indeed leaving off obedience is from the reasons that decrease one’s Eemaan. However, if this certain action of obedience was Waajib (compulsory), and one leaves it without a reason, then this is a decrease in Eemaan that one is blameworthy as well as punished for. But if it isn’t Waajib, or it is Waajib and one leaves it with an excuse, then it is a decrease of Eemaan that one is not punished for. This is why the Messenger of Allaah declared that women are deficient in ‘Aql (mentality) and Deen (Religion), and the reason he said that they had a deficiency in their Deen is because they do not pray or fast during their menses, rather they are ordered not to pray or fast, but because they are unable to practice these actions (during menses) that a man is able to practice , they decrease (in Deen) compared to a man from this perspective.
