* The attempted worship of Allaah in ways which the Prophet sallallaahu 'alaihi wa sallam did not legislate, and by ways he deemed as misguided.
* Doubting the perfection and completion of the religion of Islaam
while Allaah has said that which translates as: "This day I have
perfected for you your religion and completed my favour upon you
and have approved for you Islaam as a religion." (Al-Maa'idah: 3).
* Doubting the honesty and sincerity of the Prophet sallallaahu
'alaihi wa sallam in perfectly conveying the Message of Islaam.
* Doubting that the companions of the Prophet sallallaahu 'alaihi
wa sallam loved him, for they never celebrated his birthday.
* Making this day (Al-Mawlid) a new 'Eed wherein it is prohibited
for the Muslims to fast, as some of their people of reference have
ruled, such as Ibn 'Abbaad and Ibn 'Aashir.
* Imitating the Christians in the celebration that they hold for
the birthday of 'Eesaa, or Jesus, peace be upon him. As-Sakhaawi,
may Allaah have mercy upon him, claimed that: "If the people of the
cross celebrated the night of the birthday of their Prophet, then
the Muslims are worthier to celebrate and honour their Prophet".
Mullaa 'Ali Qaari, may Allaah have mercy upon him, refuted him by
saying: "What answers him (i.e., As-Sakhaawi) is that we Muslims
were commanded to differ from the people of the book."
* Believing that the night of the Prophet's birth is better than
the night of decree, or Al-Qadr as ruled by Al-Qastallaani, may
Allaah have mercy upon him but Mullaa 'Ali Qaari, may Allaah have
mercy upon him refuted him by saying: "What Al-Qastallaani said is
strange and unacceptable because Allaah has told us about the
virtue of the night of Al-Qadr in the Qur'aan, Allaah says (that
which translates as): "The Night of Decree is better than a
thousand months" (Al-Qadr: 3) yet there is no evidence proving the
virtue of the Prophet's birthday in the Qur'aan, Sunnah or by any
of the Muslim scholars."
* Extravagant spending during Al-Mawlid. Shaykh Muhammad Al-Mutee'i
may Allaah have mercy upon him, said: "If only the people knew just
how much the Faatimi people used to spend during this celebration,
then they would definitely deem it to be unlawful."
* Some prohibitions of Al-Mawlid include:
- Using musical instruments, as is the case in some countries.
- Lack of respect of the Book of Allaah, due to the people
combining its recitation with listening to music.
- Free mixing between men and women.
- Deeming that which is unlawful to be lawful and vice versa solely
in order for it to be practiced on that night (Al-Mawlid).
- Narrating fabricated and extremely weak Ahaadeeth which was
condemned by the falls in the saying of the Prophet sallallaahu
'alaihi wa sallam: "He who narrates something on my behalf
suspecting that what he is saying might be a lie, is one of the
liars." (Bukhaari). He sallallaahu 'alaihi wa sallam also said:
"Let he who intentionally and falsely attributes words to me expect
his seat in Hell Fire." (Bukhaari& Muslim).
- The false belief that during this night there is an hour in which
supplications are not rejected by Allaah, and that anything a
person asks for within this hour, will be granted by Allaah, just
like the hour every Friday (which incidentally is substantiated in
the Islamic texts).
- Reciting poetry and prose in praise of the Prophet sallallaahu
'alaihi wa sallam which borders on, and in some cases falls into
clear Shirk. source: alminbar.com