Question: There are some people who organize celebrations on the birthday of the Messenger (صلى الله عليه وسلم) and greet the visitors whom they have invited; and on this day, they read the Qur’an and the Seerah of the Prophet (صلى الله عليه وسلم) and make religious invocations. They do the same kind of thing on the night of Al-Isra’ wal-Mi’raj, and they give charity in the form of money and food. Are such actions permissible or forbidden?
Answer: There is no doubt that love of the Messenger (صلى الله عليه وسلم) is an obligation upon every Muslim; indeed a person’s faith is not complete until the Messenger (صلى الله عليه وسلم) is move beloved to him than his father, his son, himself and all people. Nor is there any doubt that a part of loving him is to extol him, obey his law, follow his guidance, and not to allow anyone to put himself before him, nor place in his law anything which is not a part of it, because whoever worshipped Allah in a way which was not prescribed for His worshippers by Him or His Messenger (صلى الله عليه وسلم) has accused the Messenger (صلى الله عليه وسلم) of negligence or failing to complete the Message, and no Muslim can concede this.
This is why he (صلى الله عليه وسلم) warned us to beware of innovations, saying:
“Beware of newly invented matters, for every innovation is misguidance.” 
He ordered us to follow his Sunnah and the Sunnah of the noble, Well-Guided Caliphs who came after him. There is no doubt that extolling the Prophet (صلى الله عليه وسلم) is an act of worship, and if one were to extol him through actions which were not legislated by the Sunnah, it would be a despised innovation. Celebrating the birthday of the Prophet (صلى الله عليه وسلم) by holding parties and giving charity and organizing festivities and such like on that day are all innovations without the slighest doubt. The believing person is obliged to hold firm to what has been confirmed as emanating from the Prophet (صلى الله عليه وسلم), which is sufficient. As for this innovated thing, he (صلى الله عليه وسلم) has warned us against it, and anything which he warns against contains no good in it whatsoever. Were there any good in it, his Companions, may Allah be pleased with them, would have been the first to practice it. The innovation of celebrating his birthday did not begin until the fourth century after the Hijrah and that was following the first three centuries which were the best, and if it was correct, they would have done it before us. If you are truthful, then it is incumbent upon you to obey the Prophet (صلى الله عليه وسلم), for in doing so is (all) goodness and success, so abandon such things, O my muslim brother.
The most surprising thing is that some people hold firmly to this innovation, as if they consider it an obligation of the highest order. You see them behaving negligently towards many matters from the Sunnah, which have been authentically reported from the Prophet (صلى الله عليه وسلم). It is incumbent upon (such) a person to turn in repentance to Allah and to return (to the Sunnah) and say: “We hear and obey” It has been authentically reported from Imam Malik (may Allah have mercy on him) that he said: “Nothing will reform the last of this community (i.e. the Muslims) except that which reformed the first of it.”
We say the same thing regarding Al-Isra’ wal-Mi’raj, for nothing has been authentically reported from the Companions, may Allah be pleased with them – nor the best (i.e. the first) generations – to say that they celebrated it; and if celebrating it was part of the Law of Allah, the Messenger (صلى الله عليه وسلم) would have made it clear to us, and he would have called upon his Companions and his people to do it.
Lastly, I would like to say that it is not confirmed that the Prophet (صلى الله عليه وسلم) was born on the twelfth day of Rabi’ Al-Awwal nor the night thereof, nor that his Ascension (Al-Mi’raj) took place on the night of the seventeenth of Rajab; in fact, some of the scholars say that he was born on the ninth of Rabi’ Al-Awwal, not the twelfth. Likewise, the ascension, as it is well known that it took place in Rabi’ Al-Awwal and this is nearer to the truth, though there is also some doubt about this. It has not been authentically reported that the ascension occurred in Rajab, nor in Ramadhan, nor in Rabi’. Therefore, celebrating his birthday and Al-Isra’ wal-Mi’raj are innovations without any basis…neither legal nor historical. Thus logic and tradition demand that we do not celebrate these anniversaries.
 Ahmad 4:126-127
 Hijrah: Migration of the Prophet (صلى الله عليه وسلم) and his Companions from the persecution and intolerance of Makkah to the freedom and safety of Madinah
 Al-Baqarah 2:285]
Taken from Fatawa Islamiyah, Darussalam, Volume 1 – Creed, p. 200 – 202