For a person who has converted to Islam

Question: A foreign friend of mine has just become a Muslim. What should we teach him before all else?
ANSWER
First of all, you must teach him “îmân”; that is, you must teach him Allahu ta’âlâ, His Attributes, Hadrat Muhammad’s being His Prophet, the six tenets of belief in the Âmantu, and then the five fundamentals of Islam. After teaching the foregoing, you should help him perform namâz [ritual prayer]. For it is purported in a hadîth-i sharîf:
(When you are sent on a mission to a tribe whose people are Ahl-i Kitab [the people of the Book], firstly invite them to say “Lâ ilâha ill-Allah Muhammadun Rasûl-Allah.” If they accept your invitation, notify them that it is fard to perform the five daily namâzes. If they also accept this, let them know that Allah has made the zakat that is taken from the rich and given to the poor fard.) [Bukhârî, Muslim, Abû Dâwud]

In the above-mentioned hadîth-i sharîf, belief in Allah as well as confirmation of His Prophet takes priority over others. A person who does not confirm the Prophet of Allah is not a Mu’min and Muslim.

Question: Is it necessary for a person who has just become a Muslim or for a child who has reached the age of discretion and puberty to say the Kalima-i shahâdat first, to learn its meaning, and to believe in it?
ANSWER
Yes, it is necessary. Afterwards, one has to learn and believe in the credal tenets written in the books of Ahl as-sunnat scholars.

Following this, one has to learn tenets pertaining to religious practices from the books of any of the four righteous madhhabs; that is, one has to learn and believe in the five fundamentals of Islam and halâl [permitted] and harâm [prohibited] acts; and one has to lead a life accordingly. Unless one believes that it is necessary to learn and to live up to them and unless one considers them important, one becomes a renegade. In other words, after becoming a Muslim by saying the Kalima-i shahâdat, one becomes a disbeliever yet again.

If a Muslim girl with nikâh [marriage contract as prescribed by Islam] does not know Islam when she reaches puberty, her nikâh becomes void [she becomes a renegade]. The Attributes of Allahu ta’âlâ must be told to her, and she must repeat them and say, ‘‘I believe these.” (Durr-ul-mukhtâr)

In explaining this, Hadrat Ibni ‘Âbidîn states:
If the girl is little, she belongs in her parents’ faith; she is a Muslim. When she reaches puberty, she does not belong to her parents’ faith any longer. If she reaches puberty being unaware of Islam, she becomes a renegade. Even if (s)he who has heard of the credal tenets of Islam but has not believed in them utters the Kalimat at-tawhîd (Lâ ilâha ill-Allah Muhammadun Rasûl-Allah), (s)he is not a Muslim. A person who believes the six tenets expressed in “Âmantu billahi ...” and who says ‘‘I accept the commandments and prohibitions of Allahu ta’âlâ’’ is a Muslim.

Muslims must do their best to get their children to memorize the Âmantu and must teach them its meaning precisely. If children do not learn the six tenets of belief and do not utter their faith in them, they are not Muslims, but renegades, when they reach puberty.

It does not suffice to say “I believe in Allah.” One who has denied any of the six tenets of belief, e.g. faith in qadar, becomes a disbeliever, and all of one’s good deeds perish. (Radd-ul-mukhtâr)
Question: If a disbeliever says, “Bury me in accordance with Islam,” can we consider that person a Mu’min?
ANSWER
No, you cannot. If that person says the Kalima-i shahâdat and its meaning, then you can.

Question: I have just become a Muslim. I do not have enough knowledge of religious practices. I am learning everything from scratch. Therefore, I do not know in detail acts and statements that cause disbelief. If I unknowingly say or do something that is a sign of disbelief, what will be then? If I do it without knowing, do I lose my îmân [belief]?
ANSWER
No, you do not lose your îmân. A person who has become a Muslim in such a country as Poland cannot know all things that cause disbelief. As that person cannot know all things, we should not say, “You become a disbeliever.” What to do then? It will be enough to say: “I believe Allahu ta’âlâ and His Messenger, and I believe, love and accept all the messages he (the Prophet ‘alaihissalâm’) brought from Allahu ta’âlâ. I love the friends of Allahu ta’âlâ and His Messenger, and I hate their enemies.” A person who feels uncertain about something conveyed by our religion must say, “I believe whatever Allahu ta’âlâ and His Messenger mean by this.”
Note: In the other articles, there is detailed information about six tenets of belief in the Âmantu.