Prohibition of assimilation to unbelievers

Allah said : “Is it not time for the hearts of believers to humble themselves at the mention of Allah and that which is sent down from the truth, and so that they do not become like those to whom the Scripture was given before” [Al-Hadid, 16]. Ibn Kathir said: “In this Ayat, Allah forbade the believers to become like those who were given the Scripture before them. ”See “Tafsir Ibn Kathir”, 8/20

The Messenger of Allah said: “The one who became like any nation is one of them”
Ahmad, 2/50; Ibn Taymiyyah said that the transmission of the Hadith is good. See Iqtida al-syrat, 1/236

The Prophet (peace and blessings of Allah be upon him) also said: “He is not one of us who becomes like others besides us. So do not be like the Jews and Christians” At-Tirmidhi, 4/159. “Silsilya al-sahiha”, 2194

Ibn ‘Aqil said: “These censures of assimilation mean its prohibition, not unwillingness
See Al-Salihi in Al-Furu, 9/343

Abdurrahman Ibn Ganm said: “I wrote down from the words of ‘Umar Ibn Al-Khattab his message, in which he instructed the population of Sham, in which it was said: “In the name of Allah, the Most Merciful, the Merciful. This is the message of the servant of Allah ‘Umar, the Lord of the Faithful. In relation to Christians, it is necessary to do this and that “until I reached the point” do not become like them in anything from clothes, hats, turbans, shoes, hair, do not talk with their manner of speech, do not be like them in names “Al-Bayhakyi, 2/209. Isnad is good