Question

I am a Muslim female who is 23 years old. I have always admired my religion (Islam/Sunni), and always wanted to be a good Muslim, trying very hard to do what a real Muslim woman should be doing.

My concern is I am in love with a Christian man who works with me where I work. I have tried hard to remind myself of what a severe punishment a Muslim girl would have if she married a Christian. But fortunately, he is very interested in Islam, and is willing to convert as he learns more about our wonderful religion.

Please tell me if he converts, is it okay to marry him, or will Islam have doubts about his real reasons of converting whether it is because if he really believes in Islam or because it is the only way for him to marry me?

How can I know what is in his heart truly? I am sure that he believes in Islam, but I am also sure that if he had never met me he would never convert so I am the motivation for him to convert, is that OK in Islam?

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Answer

Once a person declares that he is a Muslim by saying the Kalima (la illa ha illa Allah) verbally, then that person's life, honour and property is protected in Islam -- period.

On the authority of the Prophet of Islam himself, once a person declares the Shahada, it is not for other Muslims to question the sincerity of such a person because what is in the heart of a person is known only to Allah, s.w.t. and nobody else. However, if the conduct of such a person happens to be such that his actions openly contradict his words, for instance if the person says or does publicly such things that would indicate his belief or commitment to atheism or his intentional refusal to accept and obey the Divinely commanded obligations (e.g. salat, zakat, fasting, and Hajj), then other Muslims would be justified in doubting his sincerity and in fact he will thus remove himself from the pale of Islam. However, it should be remembered that if a Muslim person fails to perform such obligations out of sheer laziness or neglect, then he would remain a Muslim, although a sinful one.

We have attached the following hadiths which are relevant to your question.
 
 

All quotes are from Sahih Muslim -- Kitab al-Iman (The Book of Faith)

Page 1 footnote 1: (the translator, Abdul Hamid Siddiqi, added these footnotes to to the English Translation) 

Faith (iman) has two aspects - cognitive and volitional. It is at once and affirmation of truth from the depth of one's heart and a surrender to the truth affirmed. When the volitional aspect is emphasized, we have the notion commonly denoted by the word "trust"; when the cognitive aspect is stressed, we have belief. The word 'iman' signifies originally 'conviction of the heart,' while Islam signifies originally 'submission' and hence is primarily action. 
 

In this connection it would seem appropriate to quote Maulana Muhammad Abdul Aleem Siddiqui from one of his lectures where he says . . . "to recite the kalima (the Islamic Creed: there is none worthy of worship except Allah and Muhammad is His Prophet) with the tongue is meaningless unless it expresses the corresponding conviction. And conviction means nothing less than actually submitting oneself to God's commands and the Holy Prophet's leadership. It comprehends within itself the whole sweep of Islamic life."

Page 3 footnote 6: Iman (faith) may be described as the mental state of assurance or conviction in which mind accepts and endorses its experience as corresponding with Reality - the Reality, assented to and endorsed in the case of religious beliefs, of course being of a far wider, far deeper and far more comprehensive nature than reality elsewhere. With faith or belief in the sense, there invariably emerges a sense of security, a feeling of satisfaction that the road to salvation has been found - a subsuming of oneself in all-compromising Reality. 

Page 3 footnote 9: Ihsan means beneficence, performance of good deeds, but in the religious sense it implies the doing of good deeds over and above what is just in fair. It is indicative of the intense devotion of man to his Creator and Master and his enthusiasm for virtue and piety. What implies by the term tasawwuf in Islam is nothing but Ihsan. The aim of Ihsan is to create a sense of inner piety in man and to train his sensibilities in a way that all his thoughts and actions flow from the fountainhead of the love of God. 

Sahih Muslim Book 001, Number 0004: 

Abu Huraira reported: One day the Messenger of Allah (may peace be upon him) appeared before the public that a man came to him and said: Prophet of Allah, (tell me) what is Iman. Upon this he (the Holy Prophet) replied: That you affirm your faith in Allah, His angels, His Books, His meeting, His Messengers and that you affirm your faith in the Resurrection hereafter. He (again) said: Messenger of Allah, (tell me) what does al-Islam signify. He (the Holy Prophet) replied: Al-Islam signifies that you worship Allah and do not associate anything with Him and you establish obligatory prayer and you pay the obligatory poor-rate (Zakat) and you observe the fast of Ramadan. He (the inquirer) again said: Messenger of Allah, what does al-Ihsan imply? He (the Holy Prophet) replied: That you worship Allah as if you are seeing Him, and in case you fail to see Him, then observe prayer (with this idea in your mind) that (at least) He is seeing you. He (the inquirer) again said: Messenger of Allah, when would there be the hour (of Doom)? He (the Holy Prophet) replied: The one who is asked about it is no better informed than the inquirer. I, however, narrate some of its signs (and these are): when the slave-girl will give birth to her master, when the naked, barefooted would become the chiefs of the people - these are some of the signs of (Doom). (Moreover) when the shepherds of the black (camels) would exult themselves in buildings, this is one of the signs of (Doom). (Doom) is one of the five (happenings wrapped in the unseen) which no one knows but Allah. Then he (the Messenger of Allah) recited (the verse): "Verily Allah! with Him alone is the knowledge of the hour and He it is Who sends (down the rain) and knows that which is in the wombs and no person knows whatsoever he shall earn tomorrow, and a person knows not in whatsoever land he shall die. Verily Allah is Knowing, Aware. He (the narrator, Abu Huraira) said: Then the person turned back and went away. The Messenger of Allah (may peace be upon him) said: Bring that man back to me. They (the Companions of the Holy Prophet present there) went to bring him back, but they saw nothing there. Upon this the Messenger of Allah remarked: he was Gabriel, who came to teach the people their religion. 

Book 001, Number 0173: 

It is narrated on the authority of Miqdad b. Aswad that he said. Messenger of Allah, you just see (here is a point): If I encountered a person amongst the infidels (in the battlefield) and he attacked me and struck me and cut off one of my hands with the sword. Then he (in order to protect himself from me) took shelter of a tree and said: I become Muslim for Allah's sake. Messenger of Allah, can I kill him after he had uttered this? The Messenger of Allah (may peace be upon him) said: Do not kill him. I (the narrator) said: Messenger of Allah, he cut off my hand and uttered this after amputating it; should I then kill him? The Messenger of Allah (may peace be upon him) said: Don't kill him, for if a you kill him, verily he would be in a position where you had been before killing him and verily you would be in a position where he had been before uttering (Kalima). (see footnote 172) 

footnote 172: 

This part of the Hadith has been interpreted differently by different authorities but, according to Imam Nawawi, the most appropriate meaning is given by Imam Shafi'i and Ibn Qassar: When he made a profession of la ilaha ill-Allah and embraced Islam, he became a Muslim like you and his life was protected, and when you killed him, you came to his position and the protection was withdrawn. 

The point stressed in the hadith is that when a man makes a profession of Islam, he should be treated as a Muslim and we should not try to probe his intention, because Allah alone knows what is there in the mind of a man. 

Book 001, Number 0176:

It is narrated on the authority of Usama b. Zaid that the Messenger of Allah (may peace be upon him) sent us on a raiding party. We raided Huraqat of Juhaina in the morning. I caught hold of a man and he said: There is no god but Allah, I attacked him with a spear. It once occurred to me and I talked about it to the Apostle (may peace be upon him). The Messenger of Allah (may peace be upon him) said: Did he profess "There is no god but Allah," and even then you killed him? I said: Messenger of Allah, he made a profession of it out of the fear of the weapon. He (the Holy Prophet) observed: Did you tear his heart in order to find out whether it had professed or not? And he went on repeating it to me till I wished I had embraced Islam that day. Sa'd said: By Allah, I would never kill any Muslim so long as a person with a heavy belly, i.e., Usama, would not kill. Upon this a person remarked: Did Allah not say this: And fight them until there is no more mischief (see footnote 176) and religion is wholly for Allah? Sa'd said: We fought so that there should be no mischief, but you and your companions wish to fight so that there should be mischief. 

footnote 176: 

This is a Quranic verse (ii 193) in which the aim of fighting in Islam is determined. The Muslims have been exhorted to fight neither for imperialistic designs nor for personal glory but to eradicate mischief from human society. 

Book 001, Number 0177: 

It is narrated on the authority of Usama b. Zaid: The Messenger of Allah may peace be upon him) sent us to Huraqat, a tribe of Juhaina. We attacked that tribe early in the morning and defeated them and I and a man from the Ansar caught hold of a person (of the defeated tribe). When we overcame him, he said: There is no god but Allah. At that moment the Ansari spared him, but I attacked him with my spear and killed him. The news had already reached the Apostle (peace be upon him), so when we came back he (the Apostle) said to me: Usama, did you kill him after he had made the profession: There is no god but Allah? I said. Messenger of Allah, he did it only as a shelter. The Holy Prophet observed: Did you kill him after he had made the profession that there is no god but Allah? He (the Holy Prophet) went on repeating this to me till I wished I had not embraced Islam before that day. 

Book 001, Number 0178: 

It is narrated by Safwan b. Muhriz that Jundab b. 'Abdullah al-Bajali during the stormy days of Ibn Zubair sent a message to 'As'as b. Salama: Gather some men of your family so that I should talk to them. He ('As'as) sent a messenger to them (to the members of his family). When they had assembled, Jundab came there with a yellow hooded cloak on him, He said: Talk what you were busy in talking. The talk went on by turns, till there came his (Jundab's) turn. He took off the hooded cloak from his head and said: I have come to you with no other intention but to narrate to you a hadith of your Apostle: Verily the Messenger of Allah (may peace be upon him) sent a squad of the Muslims to a tribe of the polytheists. Both the armies confronted one another. There was a man among the army of polytheists who (was so dashing that), whenever he intended to kill a man from among the Muslims, he killed him. Amongst the Muslims too was a man looking forward to (an opportunity of) his (the polytheist's) unmindfulness. He (the narrator) said: We talked that he was Usama b, Zaid. When he raised his sword, he (the soldier of the polytheists) uttered:" There is no god but Allah," but he (Usama b. Zaid) killed him. When the messenger of the glad tidings came to the Apostle (may peace be upon him) he asked him (about the events of the battle) and he informed him about the man (Usama) and what he had done He (the Prophet of Allah) called for him and asked him why he had killed him. He (Usama) said: Messenger of Allah, he struck the Muslims and killed such and such of them. And he even named some of them. (He continued): I attacked him and when he saw the sword he said: There is no god but Allah. The Messenger of Allah (may peace be upon him) said: Did you kill him? He (Usama) replied in the affirmative. He (the Holy Prophet) remarked: What would you do with:" There is no god but Allah," when he would come (before you) on the Day of Judgment? He (Usama) said: Messenger of Allah, beg pardon for me (from your Lord). He (the Holy Prophet) said: What would you do with:" There is no god but Allah" when he would come (before you) on the Day of Judgment? He (the Holy Prophet) added nothing to it but kept saying: What would you do with:" There is no god but Allah," when he would come (before you) on the Day of Judgment?