His brother, Edip Yüksel, is US-based lawyer who has become known for converting to Quranism and advocating Rashad Khalifa's teachings (for which he was rejected by Metin and called a murtad by their father).
Growing up during the turbulent 1960s and 1970s, when the deadly political conflict took place in Turkey, Yüksel began his activism at an early age.
Inspired by the ideas of his father and others, Yüksel quickly became active in the burgeoning Islamist movements that emerged in the early 1950s, following the onset of the multi-party period in 1945.
On February 23, 1979, Yüksel was shot and killed in the courtyard of Istanbul's Fatih Mosque by Grey Wolves loyal to the MHP after getting into a short-term verbal argument with a group of Idealists who had threatened him.
Every year on the anniversary of his death, supporters make pilgrimage to the spot where he was assassinated, in the yard of Fatih Mosque.