Difference between Imaan and Islam
In the name of Allah, the most Beneficent, the most Merciful.
According to the Shariah, Imaan is to accept and verify the information given by the Prophets and Messengers on the basis of having full trust and reliability upon them when they give information to us regarding the Commandments of Allah (SWA), who is hidden from our sight. They also inform us about things, which are not visible. For example, Imaan means to accept as true the existence of the angels, although one has never seen them. Imaan is not to believe in the existence of angels at the time of death when the angles appear before one. This acceptance will be due to ones own seeing and not owing to ones own trust in the Prophets and Messengers of Allah.
Islam means to obey the Commandments of Allah (SWA) in the way shown to us by the Prophet of Allah Sallallahu Alahi Wasalam. Islam is not to follow Allah (SWA) according to ones own understanding. When a person follows and accepts the way of the Prophet and Messengers of Allah Sallallahu Alahi Wasalam, then it will be said that this obedience is Islam.
Although Imaan is to accept with the heart, nevertheless an integral part of Imaan is to accept Islam. That is to follow and obey the commands of the Shariah. In the Shairah, only that Islam is acceptable which is coupled with Imaan. (Aqaaidul Islam p.173-p.174)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham