All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
There is a difference of opinion among the scholars about the factors of suitability and competency in marriage. The most preponderant opinion is that the criteria are religion and good moral conduct.
Moreover, the most preponderant opinion is that family lineage is not a condition of suitability and competency in marriage. For instance, Zayd Ibn Haarithah married Zaynab Bint Jahsh despite the fact that he was not from Quraysh and she was. For more, please refer to Fataawa ">89791 and 85252.
Therefore, people should be advised and admonished to act in light of the above evidence.
It should be noted that it is an obligation to avoid triggering sectarianism as it is a characteristic of the people of the pre-Islamic era of ignorance. Allaah Says (what means): {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 Allaah is the most righteous of you. Indeed, Allaah is Knowing and Acquainted.}[Quran 49:13]
For more benefit, please refer to Fatwa 87526.
Allaah Knows best.