Luke alone, among the evangelists, begins his gospel with a formal, literary prologue which is classical in style and is comparable to the classical literary prefaces of the Greek-Roman writers of his time. He relates his book to other contemporary works of literary importance. The elegance and perfection of the Greek composition of the prologue betrays Luke’s literary ability. It also shows that Luke has an educated audience in mind. He acknowledges his indebtedness to others before him who have written or compiled narratives of the Christ-event. Among these can be included Mark. Luke expresses his conviction that these writers have been faithful to the traditions handed on by “eyewitnesses” and “ministers of the word”, namely, the apostles and others (Lk 1: 2). By tracing the sources of his account to the apostolic witnesses and preachers, and by affirming his dependence on these sources Luke assures the authenticity of the traditions concerning Jesus and, consequently, the reliability of his own account. It is evident that he makes his own singular contribution, even though he acknowledges his dependence on earlier sources.
Luke assures the readers that his gospel is the result of a careful and thorough research and that, therefore, his work is characterized by completeness and accuracy. He further assures that what he sets out to furnish is an orderly or systematic presentation. It is important to note that Luke understands the events (in RSV Bible: “things”), which form the subject matter of his book, as “accomplished” or fulfilled by God (Lk 1: 1). He thereby implies that these events, namely, the ministry, death, and resurrection of Jesus, are the fulfilment of God’s plan promised in the Old Testament (Cf. Lk 4: 21; 24: 44; Acts 1: 16, 25). Therefore, what he writes is not mere history but the history of salvation accomplished in Jesus. His goal is not a chronological presentation of events. His is an eminently theological purpose. Indeed, the emphasis of the entire prologue is on Luke’s purpose in writing the gospel:- “that you may know the truth concerning the events of which you have been instructed” (Lk 1: 4). Luke also wants to assure Theophilus and other readers of the solidity and reliability of the teaching imparted by Church in Luke’s time.
The prologue is generally understood also to cover Luke’s second volume, the Acts of the Apostles (Cf. Acts 1: 1-2). Both the gospel and the Acts are written by Luke and are dedicated to a certain ‘Theophilus’, an important person, who is otherwise unknown to us. Theophilus may have probably been a catechumen who was being instructed (katechetes) in the Christian faith. However, the gospel is addressed to all ‘that they may know the truth’ – the Christ-event (Lk 1: 4).