Abdus Salam belonged to a school/sect of Islam that encourages open debate and promotes a scientific interpretation of the Quran.
"Salam was an Ahmadi Muslim, who saw his religion as a fundamental part of his scientific work.
...
In 1974, the Pakistan parliament made the Second Amendment to the Constitution of Pakistan that declared Ahmadi to be non-Muslim. In protest, Salam left Pakistan for London." [0]
"Salam was an Ahmadi Muslim, who saw his religion as a fundamental part of his scientific work. ... In 1974, the Pakistan parliament made the Second Amendment to the Constitution of Pakistan that declared Ahmadi to be non-Muslim. In protest, Salam left Pakistan for London." [0]
[0]https://en.wikipedia.org/wiki/Abdus_Salam#Religion