The Quran makes only passing reference to racial or ethnic categories. One verse refers to "the variety of your tongues and hues" as one of the many signs of God's divine power (30:22). Another proclaims the primacy of piety over racial or tribal distinction: "O mankind, we have created you male and female, and appointed you races and tribes, so that you may know one another. Surely the noblest among you in the sight of God is the most godfearing of you" (49:13). Revealed to a largely homogeneous Arab ethnic community, explicit ethnic or racial stratification and prejudice are absent from the Quran. The most fundamental category of differentiation and identification in Islam's sacred scripture is that of religion, of the new community of Muslims as "the best community [ umma ] ever brought forth to men" (3:106), and hence as the central focus of loyalty and affiliation for a believer."
Hence, Islam focuses on the state, not on nations.
"East Pakistan" was created out of the partition of Bengal. The people were all Bengali speaking people. It is only natural that they would not accept the imposition of an "external" and foreign language. While the basis of division of districts and subsequent migrations to and from the 2 Bengals were all tumultuous scarring events, never has Bengal been Urdu speaking.
for example, a Malayalam-speaking Sunni Muslim from southern India really have more in common with a Punjabi Shia from the North than with his Hindu neighbor.There existed vast differences in language, culture and religious interpretations but both Muslims they were united by a common faith.
After Bangladesh was declared independent in 1971, then-Indian Prime Minister Indira Gandhi declared the Two Nation Theory "dead".
when you have weaknesses in your belief, you are divided into different ethnic group and this is a sign of how you lose your bond with Allah.
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. Indians delusional understanding of Pakistani's and their culture remains vague just like their history. 
