A lot of Sacred Scripture is read at Sunday Mass over the course of a year. Even so, the Bible as a whole is not read cover-to-cover, and no particular book of the Bible is read from beginning to end.
The First Reading at Sunday Mass is usually from the Old Testament. We read from the Old Testament because it helps us to understand Jesus (who was raised as a religious Jew), as well as his teachings and example.
Part of the plan for the selection of the Bible passages is to pair the First Reading and the Gospel, perhaps because they have similar themes, or because the Gospel talks about the fulfillment of what is spoken of in the First Reading.
This is part of a series on how to worship at Holy Mass by Archbishop Jackels. The name comes from the "4 H's" of the 2nd Mission Priority: Enhancing the Sunday assembly for Holy Mass. This series was published between February and December of 2017.