What are the similarities between the Old Testament and the New Testament?

A key similarity between the Old and New Testaments is that both are dedicated to the worship of the same God. Beginning with the Book of Hebrews, arguably the earliest book in the New Testament, we find Jesus described as the high priest in heaven, a parallel to the Old Testament high priests on earth.

The authors of the four New Testament gospels made frequent allusions to the Old Testament, using many passages from it to foreshadow the life of Jesus. The gospels also contain many passages taken more or less verbatim from the Old Testament, demonstrating that the use of the Old Testament elsewhere was not accidental. For example, in Mark's Gospel, Christ's very last Words on the cross were, "My God, My God, why hast thou forsaken me?" - taken by the author direct from Psalm 22:1. Even Paul sometimes used short passages from the Old Testament in his epistles.

The genre of the Book of Revelation is apocalypse, parallelling some late Old Testament books such asEzekiel and Daniel.