Most of all Fasting is one of the 3 ways of Worship to Allah (from the 5 pillers of Islam), The other two are Salah (prayer) and Hajj(pilgrimage). Any sort of worship to Allah big or small strenthens a Muslims eman. This is because we are becoming closer to Allah and the closer we are the stronger our eman gets and Allah will be happy with us. If Allah is happy with us then we have certainaly pleased Him.
Fasting also tests our eman, it will determine if we can avoid all the rules and obligation of the fast e.g Drinking, smoking etc. The more tests we past the closer we become to Allah and so our eman wil strenghten aswell.
There are many rewards for fasting also one good deed during the month of Ramadhan can be timed by 10 to 70 times more reward which also brings us closer to Allah and makes Him happy with us.
During Ramadhan one should ask for forgiveness from the heart and tongue, and if you do this then your will also please Allah because you havnt got as much sins as before. So this will too strengthen your eman.
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