The Gospel of Mark
Our Bible comprises two sections: the Old Testament and the New Testament. The Old Testament, being the scriptures of the Hebrew tradition form the basis and foundation for both the Jewish faith and the Christian faith. The New Testament comprises the four gospels, which are accounts of Jesus' life and ministry, and letters that reflect the life and progress of the early church.
The first three gospels, Matthew, Mark, and Luke, are known as "synoptic" gospels, because they are similar in content, style, and structure. (The fourth gospel, John, is distincly different.)
The Gospel of Mark is the earliest and simplest of the synoptic gospels. Here we have the foundational theology of the synoptic tradition and the core content.