The Gospel of Mark is almost like a series of news clips about the life of Jesus. It presents the life of Christ with a fast-paced approach. This gospel includes everything from ministry highlights (miracles, healings, and teaching) to the death and resurrection of Jesus.
Some have speculated that the Gospel of Mark was written during a time of serious Christian persecution (just after Jesus' death). In this way, the gospel is meant to encourage believers. Jesus is portrayed a suffering servant as well as the Savior of the world.
Jesus' humanity is one of this gospel's key features. It is more emotional than the other three gospels and truly highlights Jesus' compassion with stories like the feeding of the 4,000, the little children and Jesus, Jesus walking on water, and of course, the many healings that Jesus performs for the lowly and societally rejected. To me, this gospel focuses less Jesus' authority (over demons, over the law, over the Pharisees/Saducees) than the other gospels. More than 40% of this gospel focuses on the suffering and sacrifice during Jesus' final week on Earth.