[Note. The following post is not a professional fatwa, my views that need sharing because a lot of Mullah’s nowadays give careless fatwas without daleel from Qur’aan and Sunnah and make Islam seem harder than it is].
All Praise be to Allah,
There is nothing wrong with wearing pants, shirts, ties and suits etc.
Islam only specifies certain guidelines for dress which are as follows:
*Clothing which is exposing and shows the 'Awrah (private parts) is not to be worn.
*Religious attire of other religions is not to be worn.
*Clothing of the opposite gender is not to be worn.
*Men should wear their clothing above the ankles.
*Men should not wear silk or gold.
The Prophet (S) and the Sahaabah (R) dressed within these guidelines but otherwise did not invent or specify a certain kind of dress or uniform distinct from the Non-Muslim Arabs they lived amongst. The Prophet (S) wore clothes from a wide variety of cultural backgrounds.
Pants, shirt and tie don’t represent any one religious or ethnic group, they are an international and secular item of clothing that are not affiliated with any religion, they are worn by Muslims, Jews, Hindus, Buddhists, Athiests, Christians, Chinese, Arabs, Africans, Latinos and Westerners alike.
Contrary to popular misconception, the tie is not a sign of the cross, the claim of some ignorant people that the tie is a sign of the cross is a blatant lie, for those who have seen a tie and a cross know that the two have nothing in common, the tie is simply a piece of clothing descended from the cravat (a type of scarf).
Today we live in a global village and there is an exchange of cultural ideas amongst the different nations more than every before, there is nothing wrong with adopting aspects of other cultures so long as they do not violate the principles of Islam.
Clothing like other aspects of culture is universal in nature, wearing pants and shirt will not make you any less Muslim or even any less Arab, Persian, Punjabi, Pashtun (or whatever your ethnicity) because all religions and ethnicities world over now dress the same and dress is no longer a discerning factor, no one religion or ethnicity has monopoly over any sort of clothing, pants and shirt is now international attire and not just Western, just as forks for eating were first used in a Muslim country but now even the Westerners use them.
Shalwar Kameez which many South-Asian Muslims regard as “Muslim dress” was actually first worn by Buddhists and today it is worn by a variety of different religious groups amongst who are Sikhs, Hindus and Muslims. The Sherwani which is also regarded as “Muslim dress” was actually first worn by Parsis. The Dhoti (or sarong in English) worn by many South and South-East Asian Muslims was originally worn by Hindus and members of other Pagan religions. The Arab thobe or Jubba which non-Arab Muslims associate with Islam was worn by Arab Mushriks, Arab Christians, Arabised Jews way before the time of our beloved Prophet (S).
May the Peace & the Blessings of Allah be upon the Prophet, his Aal and his Companions.