Biblical style is one of Croatian languages styles worth of studying and a prayer book which is studied by its language and historical side is important text of Croatish language history because it describes the language of Illyrian time. A prayer book is easy to understand because it is written expecially for people, like Juraj Dobrila, big Istrian revivalist, wrote in foreword. On the introductions pages it is written about all functional styles which Croatian standard language contains and that makes understanding of importancy of biblical style as separately functional style easier. Further, is written about history of language, closely about Croatian language in 19th century and it's shortly described life and work of bishop Juraj Dobrila after whom our University got a name. The last chapter is mostly research and in it there are elaborated disagreements about assessment language of the prayer book as language which belongs to biblical style of Croatian language. Although it is self-explanatory that the language of the prayer book belongs to biblical style because of it's metatextuality with biblical style, it was a need to prove it with analysis. Literal, spelling, phonological, morphological, morphonological and syntactical analysis it is found and exemplified that Dobrilas language in prayer book Father, Let it Be Your Will is close to members of Zagreb Philological School and that it belongs to biblical functional style.