This difference is traced back to a divergence concerning the division of innovation (bid’ah). Some scholars recognized the validity of such innovations and this was, primarily, the school of Imam Al-Shafi’i (May Allah have mercy upon him) and the head of this thought was Al-’Izzi Adin Abdul Salam (May Allah have mercy upon him). In addition, Imam Al-Qarafi (May Allah have mercy upon him) who was a Maliki, carried this same opinion, giving it great attention , explaining it in an exhaustive manner. In his discussion Al-Qarafi (ra) expanded the concept of innovation to included innovations that were commendable, highly recommended, obligatory and a disliked nature. Thus, he divided innovation into five parts: (obligatory, recommended, permissible, disliked and forbidden).
There were some scholars who failed to accept this division contending that, “Any innovation, if it appears, then it is repulsive in nature.” They did this by restricting the statement of ‘Umar (ra), regarding the tarawih prayers, “This is a good innovation” to its linguistic meaning. There was a large body of scholars who held this opinion such as Taqi al-Din Ahmad Ibn Taymiyyah, Al-Shatibi, in his book Al-’Itisam, and many scholars from the Maliki and Hanbali schools (may Allah have mercy upon all of them).
Finally, there were scholars who wrote in support of celebrating the Mawlid such as Al-Suyuti (May Allah have mercy upon him) and, at the same time, there were others who wrote against it. Thus, in my opinion, there is no need to drag this discussion out, nor continue to argue about it any longer.
Whoever wants to celebrate the Prophet’s (sa) birthday should celebrate it and avoid doing any action contrary to Islamic Law. This act should be done with an intention that it is not a sunna nor an obligatory act. If these conditions are observed, and one is careful not to contradict Islamic Law, out of sincere love for the Prophet (Peace and blessing of Allah upon him), then, Allah willing, there is nothing wrong with this action and this person will be rewarded.
Commenting on this, the Shaykh of Islam Ibn Taymiyyah (May Allah have mercy upon him) said, “Indeed, such a person will be rewarded because of his intention.” Likewise, for the one who shuns this celebration, seeking to cling to the sunna out of fear of falling into innovation, then this person will also be rewarded, Allah willing. It is important to note that this is not a big issue. Nor is it necessary to give it more attention then it deserves.
Our attention towards this issue is directed towards uniting the Muslims and curbing these differences. We base this understanding on facilitation (for both sides) and ease. This ease is not founded on an empty premise, but is referenced directly back to the Quran, traditions of the Prophet (sa), the fundamental objectives of Islamic law, and the order of the Prophet (sa) to work towards unity between others. If a contentious issue arises pertaining to a matter, we exercise great consideration and respect for both sides. This consideration is not simply an act of being overly accommodative, as some contend, or attacking those who hold weak opinions. But, this respect and consideration for differences is guided by the fact that both opinions are based on proofs from Islamic Law. In some regards these proofs are clear, and in other regards the opposite holds true. Thus, some (scholars) have provided evidences for thes acts legitimacy, and others hold proofs for the opposite. In conclusion, our stance is that both are on goodness, Allah willing, as long as this act is not mixed with some type of evil and the intention is correct.
Allah knows best.
Sincerely, Shaykh Abdullah Bin Bayyah (May Allah preserve him)
Translated by Suhaib Webb (Cairo, 2007)
Source: Ibnuazlan's blog
"Although this source just pasted by me from other source.. But i hope this article can give us many benefit and could add our knowledge about our Prophet's Birthday.........May ALLAH bless us always...And even there are a lots of controversy that we could hear from many people about the celebration of our Prophet, we as Muslim shouldn't make it such a big controvercy...What we supposed to do is always try build up our Islamic generation, keep our relationship between Muslims more tough and keep on going to "UNITE!"....... "