brother: frère / fraternel < from Latin frater / fraternalis
finger: doigt / digital < from Latin digitus / digitalis
faith: foi / fidèle < from Latin fides / fidelis
eye: œil / oculaire < from Latin oculus / ocularis
There are also noun-noun and adjective-adjective pairs:
thing/cause: chose / cause < from Latin causa
cold: froid / frigide < from Latin frigidum
It can be difficult to identify the Latin source of native French words, because in the evolution from Vulgar Latin, unstressed syllables were severely reduced and the remaining vowels and consonants underwent significant modifications.
It is estimated that 12% (4,200) of common French words found in a typical dictionary such as the Petit Larousse or Micro-Robert Plus (35,000 words) are of foreign origin (where Greek and Latin learned words are not seen as foreign). About 25% (1,054) of these foreign words come from English and are fairly recent borrowings. The others are some 707 words from Italian, 550 from ancient Germanic languages, 481 from other Gallo-Romance languages, 215 from Arabic, 164 from German, 160 from Celtic languages, 159 from Spanish, 153 from Dutch, 112 from Persian and Sanskrit, 101 from Native American languages, 89 from other Asian languages, 56 from other Afro-Asiatic languages, 55 from Slavic languages and Baltic languages, 10 from Basque and 144 (about 3%) from other languages.