Why did the prophet (saw) prohibit imitation of disbelievers?

In a Nutshell: The prophet prohibited imitation of disbelievers to distinguish the Islamic civilisation centered in Medina from other civilisations. The prohibition centers on emulating that which characterised their civilisations, polities or societies, to separate and emphasise the uniqueness of the Islamic civilisation and its truthful basis and call. Evidences The Messenger of Allah (saw) said, "He is not one of us who imitates people other than us. Do not imitate the Jews and Christians." (Tirmidhi) مَنْ تَشَبَّهَ بِقَوْمٍ فَهُوَ مِنْهُمْ "Whoever imitated some people he became one of them." (Sunan Abu Dawud 4031, Ahmed, Ibn Hibban graded it as Sahih) It was narrated from Abu Sa'eed al-Khudri (ra) that the Prophet (saw) said: "You will certainly follow the ways of those who came before you hand span by hand span, cubit by cubit, to the extent that if they entered the hole of a lizard, you will enter it too." We said: "O Messenger of Allah, (do you mean) the Jews and the Christians?" He said: "Who else?" (Sahih al-Bukhari, 1397; Muslim, 4822) It was narrated Abd-Allah ibn Umar said: The Prophet (saw) said: "Whoever imitates a people is one of them." (Abu Dawood, 3512) خالِفُوا الْمُشْرِكِينَ، وَفِّرُوا اللِّحَى، وَأَحْفُوا الشَّوَارِبَ "Act different from the polytheists. Trim closely the moustache and grow the beard." (Sahih al-Muslim 259c, Bukhari 5892) اعْفُوا اللِِّحَى، وَجُزُُّوا الشَّوَارِبَ، وَلَا تَتَشَبَّهُوا بِالَيهُودِ وَالنَّصَارَى "Let the beard grow and trim the moustache and do not imitate the Jews and Christians and dye your grey hair." (Musnad Ahmed, Vol. 2, p. 356) لََكِنْ فِي دِينِنَا أَنْ نُحْفِي الشَّوَارِبَ وَأَنْ نُعْفِي اللِّحْيَةَ "In our deen, we trim the moustache and let the beard grow." (Musanaf abi Shaybah) Abd-Allah ibn Amr ibn al-'Aas said: The Messenger of Allah (saw) saw 'Ali wearing two garments dyed with safflower and said: "These are garments of the kuffar; do not wear them." (Sahih al-Muslim 2077) Abd-Allah ibn Amr said, "Whoever settles in the land of the mushrikeen and celebrates their Nawroz (new year) and Mahrajaan (festival) and imitates them until he dies will be gathered with them on the Day of Resurrection." (Iqtida Sirat sl-Mustaqim, p.183) Juristic Views The classical scholars categorised this concept into permissible, forbidden, disliked and obligatory. Most forbade imitation of non-Muslims in those things that related to non-Muslim identification or characterisation, namely, religious practices and beliefs such as crosses, ecclesiastic clothes and so on. This, according to the Hanafi school, Malikis and majority of Shafi'is is absolutely forbidden, even taking one out of Islam subject to some conditions. Clothing and suchlike not falling into the above issue is considered permissible. Once Hisham said to Abu Yusuf (student of Abu Hanifa), when he saw him wearing sandals made from palm trees with iron, "You don't see wearing that iron as a problem?" Abu Yusuf responded, "No." Then Hisham said, "Sufyan, Thawr and Ibn Yazid disliked it because it is an imitation of Christian priests." Abu Yusuf responded, "The Prophet (saw) wore sandals with hair on them that was worn by the Christian monks." [al-Mawsua'h al-Fiqhiyah vol. 13. pg.3]. Abdullah ibn Amr (رضي الله عنه‎) said: ‎”Whoever lives in the lands of the non-Arabs and celebrates their New Year and their festivals and imitates them (in their practices) will be gathered with them on the Day of Resurrection.” [Iqtidā al-Sirât al Mustaqeem, page 183.] ___ Abu Hafs al-Kabeer, an early Hanafi scholar from the 3rd century, said: “If a person were to worship Allah for 50 years and then gift an egg to a Mushrik on the occasion of Nowruz (Persian new year) who venerates that day, he will become a Kafir and all his previous good deeds will be voided.” (Ibn Hajar in Fath Al-Bari) Ibn al-Qayyim notes, in Zad al-Maad, that when the Christians of Egypt sent the Prophet (saw) a gift of clothes made by them he wore them because they did not characterise monks nor Christians of Egypt. The scholars Al-Munaawi and al-'Alqami confirmed the same when they said: "dressing as they dress, following their way of life in clothes and some of the things they do." as did al-Qaari: "whoever imitates the kuffar, such as in how one dresses etc. or imitates the evil and immoral people, or the Sufis or the righteous, is one of the people whom he imitates, whether they are good or bad." Ibn Taymiyah (ra) said: "This at the very least indicates that it is haram to imitate them, although the apparent meaning is that the one who imitates them is a kafir." (Iqtida' al-Siraat al-Mustaqeem, p. 237) In al-Fath (1/307) it says: "If we say that it is forbidden (i.e., purple saddle pads) because it is imitation of the non-Arabs, that is for a religious reason. But that was one of their unique characteristics at that time, when they were kuffar. But now it is no longer one of their unique characteristics, this meaning no longer applies, so it is no longer makrooh." Analysis The Encyclopedia of Fiqh defines the Arabic word imitating [tashabu] to lingusitically mean: "To resemble another person." Its meaning and usage in Islamic Law does not differ, "This usage of the word by the scholars of Fiqh does not different from this meaning." (al-Maws'u al-Fiqhiyah al-Kuwatiyah, vol. 13, pg. 1) I think there is widespread confusion and misunderstanding of these ahadith of differentiation from disbelievers. They were narrated in Medina, an Islamic polity, as part of the Prophet's (saw) efforts to create characteristics that were unique to his civilisation. It is why the prohibition relates to imitating a nation (بِقَوْمٍ) in that which characterises them. Every civilisation has characteristics that distinguish it and an Islamic civilisation is no exception. We have 5 core pillars for a start, legal testification, mosques, azaans, bayt al-mal, a month of abstinence from core desires and so on. Other characteristics of jihad, millet communities, Arabic etc are well known too. Other ahadith about cultural aspects such as beards, dress codes, religious praxis add to these. They should be implemented society wide to complement the pillars and enrich them. Other practices like shura can be adopted from other religions like Judaism so long they are distinguished from other polities especially where we have greater right to them - thus allowing us to create further unique traditions for our society. This social dimension of Islam, couched in a polity and civilisation, is lost when Islam was reduced to a personal faith by colonial powers. These atomised ahkam and acts of halal / haram are applied to individuals who choose to follow or not, whilst secular nationalists innovate all sorts of kufr emulating the West, from national flags, borders, anthems, dress codes, schooling, banks etc all of which we ignore. Conclusion The prophet prohibited imitation of disbelievers to distinguish the Islamic civilisation centered in Medina from other civilisations. The prohibition centers on emulating that which characterised their civilisations, polities or societies, to separate and emphasise the uniqueness of the Islamic civilisation and its truthful basis and call.