1Inasmuch as many have taken in hand to set in order a narrative of those things which have been fulfilled among us,2just as those who from the beginning were eyewitnesses and ministers of the word delivered them to us,3it seemed good to me also, having had perfect understanding of all things from the very first, to write to you an orderly account, most excellent Theophilus,4that you may know the certainty of those things in which you were instructed.

The Savior of the world was truly born. He lived among us and was openly crucified, and then he rose from the dead and ascended to heaven. Those were the things, which had been fulfilled among his followers who received the gift of the great Holy Spirit through their faith.
This Spirit came out of them and prompted them to publish the good news of salvation all around the world. Many have written letters and books to clarify the unique person Jesus Christ to the public. All true reports about Jesus signify a gospel. This significance is rather more exact than that of the word "gospel" which was originally used in the house of Roman Caesar for official announcements, i.e. when a child was born to him, or when he won victory over the enemies. You have the right and the privilege to spread the good news of Christ’s birth and victory in the world.
When Theophilus, the Roman governor had heard much about the King of kings and Lord of lords, he wanted to know every thing exactly about the chronological events covering the Lord’s birth, death and unique resurrection. Luke, the Greek physician traveled to meet the eyewitnesses in Christ’s company and asked them about the whole details. He did not begin his gospel with the baptism of Christ at the hands of John the Baptist, but examined the mysteries of Christ’s birth carefully and traced up his life with great attention. Our faith is founded not on ideologies or philosophical ideas, but on a living person who had exerted an open and clear influence on the history of mankind.
Luke found a collection of Jesus’ sayings gathered by the apostles, the ministers of the word, and translated by them from Aramaic into Greek with all exactness and carefulness. Today, we do not have the mother of all those gospels in Aramaic. However they appear clearly in the first three gospels with power and great glory. Luke added to these sayings the reports and parables of the eyewitnesses whom he had visited and searched until he extracted, through his diligence, the precious words of Christ, which are not found in the other gospels.
We thank our Lord Jesus Christ who through his Holy Spirit guided the Greek physician Luke to write his gospel, for in his diligence the objective work becomes accurately united with the power of inspiration and the world traveler’s insight with the simple faith in God’s mercy which is the foundation of Christ’s peace to all humans.
Luke wrote his gospel to confirm to the spiritual student governor what he had learned about the incidents of Christ, not only historically, but spiritually first, so that he might be filled with God’s joy and gladness. You may also obtain this through studying the gospel if you read it with continuous prayer.

Our Lord Jesus Christ, we thank you because you rose from the dead and live and reign with the Father in one essence. We glorify you because you guided your servant Luke and many to write your gospel accurately. Please help us to hear you in their words, understand your intents, believe in your kindness, do your will, convey your salvation to others and tell them that you are the Savior of the world who preaches us personally in his unequalled gospel.
What were the principles adopted by Luke in writing his gospel?