Without Iman, the individual’s espousal of Islam as his religion would lack credibility. That is why, if he is to be a true believer, he must not only testify to his faith by word of mouth (Shahaada bil Lisan), but must also accept it with all his heart and soul and then staunchly adhere to it. Furthermore, he is obliged to do good works in keeping with the fundamentals of the faith. Both belief (iman), and right action (amal) are absolutely vital.
The Creed, or article of faith, called Shahaadah, literally means ‘witness’ or ‘testimony.’ The first of the five pillars of Islam, its nomenclature derives from the word ‘Ashhadu,’ which means ‘I declare,’ or ‘I bear witness.’ As an Islamic term, it means testifying to faith in Islam. The words of the Shahaada in Arabic are: La ilaha illa Allah Muhammad ur-rasul Allah. This means: There is no god but Allah and Muahammad is the Messenger of Allah. Its recital is called the ‘Kalimah.’
For Muslims there are certain requirements which have to be observed regarding the Kalimah of Shahaadah. They are as follows:
It has to be repeated aloud, at least once in a lifetime.
Its meaning has to be fully understood.
It should be believed in “with the heart.”
It should be professed in until death.
When spoken in Arabic and with sincerity, it is a commitment to obey God and follow the Prophet: ‘I bear witness that there is no god but Allah; I bear witness that Muhammad is the Messenger of God.’
These are the first words that are breathed into a child’s ear at birth. These are also the last words which a Muslim would utter with his dying breath.
Even if someone recites the shahaadah hypocritically— which is not acceptable to God—he will still, for practical purposes, continue to be regarded as a member of the Muslim community. Nevertheless, a proper understanding of the basic tenets is a prerequisite for all true believers. And sincere and heartfelt faith is a sine qua non if salvation is to be ensured in the life Hereafter.
Source: The Man Islam Builds