The Gospels (Greek for "good news") are accounts of Jesus as written by two of His Apostles (Matthew and John) and two disciples (Mark and Luke). The Gospels were originally written in Greek, the common lingua franca (common or commercial language among diverse peoples) of the Roman Orient. No original Gospels have been found in Aramaic; the only discovered Aramaic Gospels are translations from Greek versions. The general consensus is that the Gospel according to Matthew was written particularly for Jews; the Gospel according to Mark was written particularly for Romans; the Gospel according to Luke was written particularly for Greeks; and the Gospel according to John was written for everyone. Jesus had emphasized that scribes were part of those He sent forth to proselytize the world. "I am sending you prophets and wise men and scribes ...." (Matt 23:34 (NAS)).
Luke was a Greek physician (see Col 4:14) who accompanied Paul and also wrote the Acts of the Apostles describing the arrival of the Holy Spirit. Unlike the firsthand Gospels of Matthew and John, the Gospel of Luke records eyewitness accounts of others, much as a doctor asks a patient for his medical history and then writes it down in the medical file. Due to Luke's professional nature, his Gospel is very comprehensive about Jesus' life and resurrection, and it also conveys the great sense of joy that Jesus' family, friends and followers felt. In the Battle of the Bulge in World War II (the surprise Nazi counterattack in Dec. 1944), which was one of the worst military defeats in American history, a minister’s son who had memorized Luke's description of the Nativity recited it for his fellow soldiers on Christmas Eve while together in the trenches. Many of them died soon afterwards in battle.
The greatest writing in the history of the world is the Gospel of John, the Apostle whom Jesus loved the most. John likely revised and perfected this Gospel for decades before releasing it to others. As was typical for many of the greatest authors in history, such as Copernicus, John's work was probably not released to the public until he passed away. Isaac Newton, to take another example, delayed publication of his great mathematical discoveries for decades. John's life was devoted to writing his Gospel (and Book of Revelation), and he would be expected to improve the work as long as he lived.
American soldiers in World Wars I and II would carry copies of the Gospel of John with them as they journeyed to faraway battles. This single book has done more to shape human thought and behavior than any other work. Our uniquely American First Amendment right of free speech is based on ministers preaching of the "Word" of God as described in the first few verses of the Gospel of John.