What is the ruling on changing one's lineage—such as adopting the name of an uncle or maternal uncle—in order to obtain citizenship in a country that offers material advantages, while the individual possesses their original citizenship and documents?

Attributing oneself to other than one's father is forbidden, and it leads to lying, issues of inheritance, and prohibited degrees of kinship (mahramiyyah). The Prophet, may Allah bless him and grant him peace, warned that whoever does so will be cursed by Allah, the angels, and all mankind. This act combines lying to unlawfully consume wealth with attributing oneself to other than one's father. Whoever has done this must return to the truth, tear up the false nationality document, and repent to Allah. As for the money he acquired through this nationality, "what has passed is for him, and his affair is to Allah."