From the Bible Dictionary (Mark)
Also called John; son of Mary, who had a house of considerable size in Jerusalem (Acts 12: 12); cousin (or nephew) of Barnabas (Col. 4: 10); accompanied Paul and Barnabas from Jerusalem (Acts 12: 25) and on their first missionary journey, deserting them at Perga (Acts 13: 5, 13); accompanied Barnabas to Cyprus (Acts 15: 37-39); with Paul at Rome (Col 4: 10; Philem. 1: 24); with Peter at Babylon (i.e., probably at Rome) (1 Pet. 5: 13); with Timothy at Ephesus (2 Tim. 4: 11). His gospel (see Gospels) was possibly written under the direction of Peter. His object is to describe our Lord as the incarnate Son of God, living and acting among men. The Gospel contains a living picture of a living Man. Energy and humility are the characteristics of his portrait. It is full of descriptive touches that help us to realize the impression made upon the bystanders. Tradition states that after Peter’s death, Mark visited Egypt, founded the Church of Alexandria, and died by martyrdom.
From Janet Thomas, “Who Are Matthew, Mark, Luke, and John?,” NewEra, Jan 2007, 18–22
Mark was much younger than the other writers. His mother was a prominent follower of Jesus Christ. Acts 12:12 tells us that her house in Jerusalem was used as a meeting place for other disciples. From this verse we also learn that her son’s full name is John Mark.
Mark was also a follower of Jesus Christ but would likely have been in his teens when the Lord was in Jerusalem. He may have seen and listened to the Savior on occasion. After the Resurrection, as the Savior’s message was beginning to be spread, Mark traveled with the Apostle Paul. He then accompanied the Apostle Peter to Rome and stayed by him while he was in prison. Mark is known as Peter’s interpreter, both in speech and in writing. As a fisherman from Galilee, Peter may not have spoken Greek fluently, so Mark interpreted for him.
In his book, Mark wrote down the observations and memories of Peter, one of the original Apostles. Mark’s book reflects Peter’s interest in spreading the gospel among the Gentiles.
From Robert C. Patch, “The Gospel in the Gospels,” Ensign, Sep 1974, 38
The Gospel of Mark is the shortest in the New Testament, and biblical scholars have observed that Mark seems to be reflecting the attitude of Peter in this gospel.
But as an independent narrative, it has drama, detail, and insight. The first phrase of Mark’s gospel, “The beginning of the gospel of Jesus Christ … “seems to be an attempt to declare something most fundamental in gospel thought. What constitutes the “beginning” of the gospel for Mark?
Almost certainly it is Christ’s divine mission, for Mark gives evidence to persuade the reader that Jesus had power over death, that he was Lord of the Sabbath, that he ordained the Twelve Apostles, that he raised the dead, that he gave a correct perspective of Mosaic cleanliness, and that he publicly proclaimed that he was the Messiah. After the crucifixion, Mark culminates his narrative with an angel announcing, “He is risen.” (Mark 16:6.)
What theme does Mark employ that ties the narrative of Christ’s divinity with that of Christ’s ministry? In the first part, dealing with the Galilean ministry, we can almost see the shadow of Isaiah 61:1–2, a prophecy fulfilled by John the Baptist as forerunner.
In the narrative dealing with Christ’s divinity, Mark then records all the evidence that Jesus really was the Messiah: he preached that the kingdom was at hand; he forgave sin; he was lord of the Sabbath; he exercised power over illness, spirits, and death; he predicted his own death; and he stated that the blood of the New Testament was shed for many. (See Mark 14:24.)
The writings of Mark tell of the things that the Lord of heaven and earth did, showing his divine power and mission. Mark’s gospel is a testimony of the atonement.
Summary of Mark at NIV site: http://www.biblica.com/niv/studybible/mark.php