The race of Murgos in The Belgariad by David Eddings, are physically distinguished from other races by their angular eyes, high cheekbones and savage facial scars . It is evident through various hints in the series that these scars are of ritual application and purposefully created. The Belgariad closes with no definitive proof that Murgo scarification is a ritual necessity, however the subsequent series, The Mallorean does .
Ritual scarring is often linked to cultural identity, rite-of-passage and status . Murgo men and Grolim priests primarily wear these scars. Their god, Torak was himself disfigured, scarred by attempting to undo the power of the Orb  and thus setting the premise for the series. Murgos and Grolims seem to embody their god’s characteristics more closely than Torak’s other followers. It is therefore likely that they practised ritual scarring in an effort to more closely represent Torak.
Torak is also depicted as a bloodthirsty god, requiring sacrifices from his believers . The Grolim priests exact this savagely  and as Torak’s most reverent followers, they cut themselves in homage to him too. Before reading The Mallorean I believed Murgos branded themselves with scars. Branding uses heat to create scarification, and as Torak was burned, it was a strong possibility this is how Murgo scars are created. Torak’s lust for blood however, deems cutting as the preferred method for scarring.
Eddings, David. The Belgariad
 “His cheekbones were high, and there were several savage looking scars on his face. His eyes looked curiously angular…” The Belgariad, book 1: Pawn of Prophecy, loc 834
 “…every Murgo alive slashes his face as a blood offering to Torak.” The Mallorean, book 2: King of the Murgos, loc 5709
 Brief explanation here: http://news.nationalgeographic.com/news/2004/07/0728_040728_tvtabooscars_2.html
 “When Torak rose from the water, his right side was still fair, but his left was burned and scarred hideously by the fire of the Orb.” The Belgariad, book 1: Pawn of Prophecy, loc 121
 “Bow before my name and worship me with prayers and with sacrifices…” The Belgariad, book 5: Enchanters’ End Game, loc 128
 “… bend the Thull backward over the altar, and a third cuts his heart out.” The Belgariad, book 3: Magician’s Gambit, loc 4701