In Islam, the marriage of a man and a woman is not just a financial and physical arrangement of living together, but a sacred contract, a gift of Allah, to lead a happy, enjoyable life and continue the lineage. The main goal of marriage in Islam is the realization of tranquility and compassion between the spouses. Being a solemn contract, the Shari`ah lays down rules and arrangements for marriage to guarantee its stability. One of the basic rules regarding marriage is that a Muslim woman is not allowed to marry a non-Muslim man.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: “The definition of a Muslim is one who testifies that there is no god but Allah and that Muhammad is the servant and final Messenger of Allah; While doing so he/she must also believe in the angels, the Books, the Prophets, the Last Day, and the fact that good and bad are decreed by Allah. Besides, he/she must also accept the Five Pillars of Islam (the five daily prayers, paying Zakah, fasting during Ramadan, and making pilgrimage to Makkah once in a life-time, if one has the physical and financial ability to do so). Also, he/she must declare as lawful what Allah and His Messenger have declared as lawful and declare as unlawful what Allah and His Messenger have declared as unlawful.
Almighty Allah says: “The Messenger believeth in that which hath been revealed unto him from his Lord and (so do) the believers. Each one believeth in Allah and His angels and His scriptures and His messengers We make no distinction between any of His messengers and they say: We hear, and we obey. (Grant us) Thy forgiveness, our Lord. Unto Thee is the journeying.” (Al-Baqarah: 285)
Allah also says: “Those who follow the Messenger, the Prophet who can neither read nor write, whom they will find described in the Torah and the Gospel (which are) with them. He will enjoin on them that which is right and forbid them that which is wrong. He will make lawful for them all good things and prohibit for them only the foul; and he will relieve them of their burden and the fetters that they used to wear. Then those who believe in him, and honor him and help him, and follow the light which is sent down with him: they are the successful.” (Al-A`raf: 157)
Imam Muslim reported on the authority of `Umar, who said: One day while we were sitting with the Messenger of Allah there appeared before us a man whose clothes were exceedingly white and whose hair was exceedingly black; no signs of journeying were to be seen on him and none of us knew him. He walked up and sat down by the Prophet. Resting his knees against his and placing the palms of his hands on his thighs, he said, “O Muhammad, tell me about Islam.” The Messenger of Allah said, “Islam is to testify that there is no god but Allah and that Muhammad is the Messenger of Allah, to perform the prayers, to pay the Zakah, to fast in Ramadan, and to make the pilgrimage to the House if you are able to do so.” He said, “You have spoken rightly,” and we were amazed at him asking him and saying that he had spoken rightly. He said, “Then tell me about iman.” He (peace and blessings be upon him) said, “It is to believe in Allah, His Angels, His Books, His Messengers, and the Last Day, and to believe in Divine Destiny, both the good and the evil thereof.” He said, “You have spoken rightly.”
The Prophet also said, “Whoever prays as we do, and faces towards our Qiblah, and eats the meat we slaughter, he is the Muslim who enjoys the protection of Allah and His Messenger (peace and blessings be upon him).” (For further references, see the Qur’an 9: 29; 10:59; also hadith number 22 in the famous collection entitled Forty Hadith by Imam Nawawi).
So, what a prospective bride would ask a man who adopts the aghani khan ”religion” is to ask this person where he would place himself in regards to the above mentioned beliefs and practices which are integral to Islam. If he says that he accepts them, and abides by them, then he is considered a Muslim, and no one has any right to put him outside the fold of Islam. If, on the other hand, he does not subscribe to the above beliefs and practices, but rather he claims to adhere to some different sets of beliefs and practices, then definitely he cannot be considered a Muslim, regardless of his own false claims to the contrary.”