It is also called Iman (Faith), for a Muslim does good deeds out of belief in Allah and His Messenger (peace be upon him), not to show off or establish a reputation among people or out of hypocrisy. Rather, the true Muslim submits to Allah, follows His ordinances and observes His Restrictions out of firm faith and deep knowledge. A Muslim knows that Allah is One and has no partners and He is the Lord of the heavens. He knows that Allah is the AllKnowing Supreme Creator. Therefore, he devotes himself to Him and glorifies His Sacred Ordinances out of firm faith in Allah Who is the Lord, the God, the Creator, the AllProvider, and the One Who is rightfully worthy of worship. The Prophet (peace be upon him) stated in an authentic Hadith,
Faith has over seventy branches, the best of which is the declaration that there is no one worthy of worship but Allah, and the humblest of which is removing harmful things from the path. And shyness is a branch of faith.
Our religion is called Islam, as it is submission to Allah, truthful devotion to Him, humility to Him and glorification of Him. It is also called Iman i.e. faith, for it is belief in Divine matters e.g. Allah's Attributes, His Oneness, and that he is the true God Who alone is worthy of worship along with believing in what He has ordained, forbidden, and allowed for His servants. All these meanings are included in the words Islam and faith. Islam is called so owing to what it involves of submission to Allah, abiding by His restrictions, and observing His restrictions. It is called faith, for its truthfulness which results in continual righteous deeds and proper speech.