Abu Baker Sadiq , Usman Ghani , Umer Farooq and Hazrat Ali were True Religious Leaders and They have ruled over People, of one Religion NAMED as ISLAM , they Believe in Muhammad as Prophet and Quran as their Holy BOOK (Which the Muslims Claim free of any type of alterations since last 1500 years, and No one in the world today can prove their claim false today).
Rusia have been super Power for decades and was successful Country , whose leaders even donot believe in GOD.
China is another example of Secular Country.