Is it permissible to harbor a sexual aversion towards a certain group, believing its members to be undesirable, and to prejudge an individual because they belong to that group?

It is not permissible for a Muslim to hate his fellow Muslims merely because of differences in their nationality or affiliation, for this is an ignorant outlook that Islam has abolished. The principle of generalization is wrong, for every soul is responsible for what it has earned, and people differ in their natures. Fanaticism towards a race or people is religiously rejected, and the Prophet, peace and blessings be upon him, warned against it. Allah Almighty says: (O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another. Indeed, the most noble of you in the sight of Allah is the most righteous of you. Indeed, Allah is Knowing and Acquainted). Thus, nationalism and patriotism are wrong, ignorant concepts, and nothing is superior to piety.