Mark’s Gospel is often mischaracterised as shallow and a “young man’s excited report about this cool dude Jesus” – this is because the Greek used in its composition is very colloquial and unrefined, and Mark repeated uses the word euthus = ‘immediately’ for dramatic effect. It is a fast-paced narrative showing Jesus moving from place to place, casting out devils, healing and resurrecting the dead. It seems that he never finished it, with various later attempts to append endings. It is just not that great a piece of work and needs the other synoptics to come along and fill out the story using his work as a base.
This short essay tries to correct this misconception by demonstrating that Mark has a substantial Christology and a rich theological vocabulary. The “never finished” charge is weak as well, there is a strong indication that Mark intended his work to be performed which explains the fast-paced narrative and the abrupt ending. It is known that Mark became both a companion to Paul and Peter, so he clearly was well respected by the foundational leaders of the Church and his gospel should be respected in its own right as providing the scaffolding upon which the other gospels were built.
You can find a PDF here.