Ever since the ink dried on the last word penned in the New Testament, skeptics have sought to cast doubt on the historical reliability of the Gospel accounts regarding the life of Jesus. For if they are only mythology and fabricated stories, then the rest of the NT is built on a falsehood. After all, it is supposed, how could the Gospels be reliable, look who wrote them. Matthew was a former, despised tax-collector. John was an uneducated fisherman and Mark received his facts from Peter who was also an uneducated fisherman, rough and brash. And then there is Luke, he was a Gentile who was almost a generation removed from Christ when he penned his Gospel. Surely his Gospel can’t be reliable.
The charges of being uneducated and unlearned leveled against Matthew, Mark, and John can’t be directed toward Luke. He was well educated in Greek culture, a physician by profession, and a loyal companion of Paul from his second missionary journey to his final imprisonment in Rome (Col 4:14; Philem. 24; 2 Tim. 4:11). He was a scholar who wrote with polished clarity, his Greek exhibiting he was at home using the classical vocabulary of the learned or the vocabulary of the common man.  As a physician, Luke not only had a scientific mind but a historian’s mind, a common trait of an educated Greek. His medical training prejudiced him against accepting facts without thorough investigation and verification. Writing as a historian, even though a believer in Christ, he carefully examined and weighed all the facts as being true or false before ever penning a word. His medical and scientific background would not allow him to pen anything he deemed to be false. Archaeologist Sir William Ramsay (1851-1939) spent fifteen years seeking to disprove the historical trustworthiness of Luke’s writings (Luke and Acts) and came to the conclusion, “Luke is a historian of the first rank; not merely are his statements of fact trustworthy… [he] should be placed along with the very greatest of historians.”
Luke was written after Matthew and Mark, but before John. While there is debate, most scholars contend Luke was written between 60-70 AD. A.T. Robertson observed, “Luke writes after the close of Christ’s earthly ministry and yet it is not in the dim past.”  Written some 30 to 35 years after Christ’s earthly ministry, Luke begins his masterful narrative different from the other three Gospel writers. His style in his Preface is similar to many of the secular Greek historians. In the Greek his Preface is one sentence and is packed with information. It reads: “Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word; It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus, That thou mightest know the certainty of those things, wherein thou hast been instructed.” (Luke 1:1-4)
Luke’s Preface can be divided into four main divisions. A look at each division gives us great insight into the very intent and heart of Luke and the reliability of the Gospel he penned.
1. The Recognition of the “many” accounts of Jesus’ Life
“Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us,” v. 1-2a
In beginning his Gospel with the word “forasmuch,” Luke is acknowledging a fact already well known; that “many” had already undertaken the task of writing about the life of Jesus. How many is “many” is not known, but would indicate more than two. Matthew and Mark had already been written, and no doubt others had, as well (though they have not survived). Luke has words of commendation for the “many” narratives that sought “to set forth in order” a sequence of events concerning Christ’s life, which Luke says are “surely believed among us” (v 1). As well, he attests to the circulation of these accounts which had been “delivered unto us” (v. 2a), the Greek word translated “delivered” signifying “to transmit [by instruction] in both oral and written form”  Were these early accounts of the life of Jesus which circulated among the early Christians reliable?
2. The Reliability of the “many” accounts
“Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word.” (v. 2)
Luke affirms the oral and written accounts which circulated among them and were believed were reliable. He affirms the reliability of these accounts (1) because of Personal Examination, and (2) Practical Experience.
First, those who “delivered” these accounts were “eyewitnesses,” they had personally examined Jesus. The word for “eyewitnesses” is the Greek word (αυτοπται – autoptai). It was a medical term, from where we get the word autopsy. It means seeing with one’s own eyes. The word was used in “medical language of a personal examination of disease or some part of the body.”  Luke affirms the accounts that circulated among them were true reports because they came from those who were eyewitnesses to Jesus and had personally examined Him.
Second, those who “delivered these accounts were “ministers of the word,” they had practical experience with Jesus and facts about Jesus, who was/is the Word. The word for “ministers” (υπηρεται – hupēretai), “was used in medical terminology to refer to doctors who served under a principle physician.” Luke affirms the reliability of the circulated accounts of the life of Jesus, as they came from those who served as assistants under the Great Physician.
While Luke commends and attests to the fact that “many” sources circulating were reliable, there was born in Luke’s investigative mind the idea to write another and more comprehensive narrative about the life of Christ than those in existence.
3. The Research Involved in Luke writing his Gospel
“It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus.” (v. 3)
In verse three is revealed Luke’s (1) inner persuasion to write, (2) the investigation before writing, and (3) the inspiration while writing.
First, Luke states that “it seemed good to me also” to write an account of Jesus’ life. Since so much interest existed among Christians about Jesus’ life and the need to make his name known among unbelievers, Luke “thought it good” to write another narrative which could supplement and even be a more comprehensive account than what already existed. No doubt, this inner persuasion to write a narrative on the life of Jesus was placed in him by Holy Spirit who would not only guide Luke’s research, but guide his arranging the material in an orderly manner.
Second, before writing Luke thoroughly investigated to verify the accuracy of the facts surrounding Jesus’ life. While it is not known what sources he consulted or who all he interviewed in his research, it is clear he didn’t depend solely on the narratives of Matthew and Mark, for some 50% of Luke’s material is unique to his Gospel. He had available to him the “many” oral and written accounts already circulating and no doubt interviewed many of the eyewitnesses of Jesus’ life still living. As a trained historian his research was extensive (“all things”). The words “having had perfect understanding of all things” (KJV), are literally, “having closely traced the course of all things accurately.” The word translated “perfect” (akribos) means carefully, accurately, precisely, exactly. It was a medical term “used to indicate the accurate information gained by a doctor questioning the patient.”  Luke is clearly saying his research was carefully and accurately done. And once his research was complete, he sought to write it all “in order,” meaning he arranged his findings in an orderly fashion or chronological order.
Luke wrote nothing that he could not verify and validate to be true. Luke’s medical training and his scientific mind would have prejudiced him against believing such amazing events as John’s miraculous birth, Gabriel’s appearance to Mary, the virgin birth, the miraculous events surrounding the birth of Jesus, the many miracles Jesus performed, His resurrection and ascension. His Greek analytical mind would not readily accept such events as logical unless they could be verified and proven without doubt. The very fact that Luke records events outside the natural order of scientific laws affirms that he was so convinced of their reality that he recorded them. The miraculous events Luke records, he does so with certainty based upon his extensive research and the abundant of evidence which verified them.
Third, Luke’s research and writing were more than personal inward persuasion to produce another narrative on the life of Jesus, but was superintended by the Holy Spirit. Notice Luke says all his research was “from the first” (ανωτεν – anōthen). The phrase “from the very first” could also be translated “from above.” It is so translated in John 3:3, 31; 19:11. G. Campbell Morgan makes a most interesting suggestion. Noting the Greek word anōthen can mean either “from the first,” or “from above,” he suggests the latter meaning here. Thus, Luke is claiming that his research was under guidance “from above,” by the Holy Spirit. Morgan writes, “[Luke’s] scientific work was under the guidance of heaven itself, that he not only brought to bear upon his work his own scientific ability to sift and trace, but he sought guidance from heaven. That is how he prepared his material.”  Since Luke is in the sacred canon, and all Scripture is divinely inspired (2 Timothy 3:16), Morgan’s assertion cannot be dismissed. In Luke we find the perfect tension and balance between diligent research and the superintending of the Holy Spirit in the penning of the inspired Gospel.
4. The Reason Luke wrote his Gospel
“Most excellent Theophilus, that thou mightest know the certainty of those things, wherein thou hast been instructed.” (v. 3b-4)
Luke’s Gospel is specifically directed to “most excellent Theophilus,” whose name means “one who loves God” or “a lover of God.” Luke’s use of “most excellent” indicates Theophilus was probably a Roman official or held a high position; it was “a from of address used of persons who held a higher official or social position than the speaker.” Luke complied his narrative for the purpose that Theophilus “mightest know the certainty of those things, wherein thou hast been instructed.” Even though there had been circulating “many” oral and written narratives, Luke’s exhaustive research and producing a narrative on the life of Christ was for the precise purpose of confirming with the accuracy and certainty the previous instructions Theophilus had already received in regard to the Christian faith. 
Though initially written for Theophilus’ instruction, in God’s divine providence Luke’s narrative began to be widely circulated, and was used to instruct and strengthen the faith of all “lovers of God,” as well as to answer questions or attacks by unbelievers concerning the life of Jesus. It didn’t take long for the early Church to recognize God’s divine fingerprints on each page. Eventually becoming the third book in the New Testament, for over two thousand years countless eyes have vividly beheld the glorious life of Jesus walking upon the inspired pages.
Luke indeed is a reliable historian. His painstaking research has withstood the fires of criticism that have sought to discredit him. Time and time again this scientist-historian has endured the test of careful scrutiny. Guy Waters has stated, “What’s striking is that Luke’s care as a historian has been vindicated by research. He’s come under some pretty heavy scrutiny but he’s always been vindicated. Whether it’s the title of an official or the geographical detail, Luke always comes out shining. So, he was a meticulous historian. He took such care to ensure that we would have a faithful record.”  The Gospel of Luke assures us that the Christian faith rests on a solid historical foundation. One who reads the Gospel of Luke can do so with the utmost confidence in the reliability of the historical facts found within.
In closing, a quote by James Coffman says it well, “[Two thousand] years have not dimmed the luster of Luke’s glorious work nor cast any shadow over the hard historical facts related therein, facts which have been etched into the conscience of all mankind and which are indelibly written into the pages of the world’s authentic records.” 
 Leon Morris, The Gospel According to St. Luke, (Grand Rapids: Eerdmans, 1974), 65.
 William Ramsay, The Bearing of Recent Discovery on the Trustworthiness of the New Testament, (London: Hodder and Stoughton, 1915), 222.
 A.T. Robertson, Luke the Historian in the Light of Research, (Grand Rapids: Baker, 1977), 47.
 Rogers and Rogers, Linguistic and Exegetical Key to the Greek New Testament, (Michigan: Zondervan, 1998), 106.
 Rogers and Rogers, 106.
 Herschel H. Hobbs, An Exposition of the Gospel of Luke, (Michigan: Baker Book House, 1966), 19.
 Kenneth S. Wuest, Word Studies in The Greek New Testament, (Grand Rapids, MI: Eerdmans, 1979), 52-54.
 Hobbs, 21; Rogers and Rogers, 106.
 G. Campbell Morgan, The Gospel According to Luke, (New Jersey: Fleming H. Revell, 1931), 13.
 Rogers and Rogers, 106.
 J. R. Dummelow, Commentary on the Holy Bible, (New York: Macmillan Company, 1937), 736.
 Quote from an interview with Dr. Guy Waters, professor of NT at Reformed Theological Seminary, “Luke the Historian,” 5 Minutes in Church History, October 7, 2015.
 James B. Coffman, Luke, (Abilene Christian University Press, 1974), 10.