The unknown author of the Book of Hebrews wrote to the entire Jewish community, including those who had converted to Christianity and those who, for one reason or another, had not.
At the time of the book’s writing, anti-Christian sentiment was high, and many in the Jewish community were hesitant to convert. Judaism had roots going back thousands of years and was under Rome’s protection. Christian converts were being persecuted on different levels, ranging from excommunication from Jewish temples to torture. Many were reverting to old Jewish customs to avoid persecution.
The Book of Hebrews draws heavily from Old Testament passages in order to address the fears of the Jewish people, showing how the old laws and teachings were always pointing towards the coming of Jesus, who would supersede the need for sacrifices and other such rituals. It also stresses Christ’s human nature. Jesus became “like his brothers in every way”, subject and subjected to the same temptations and suffering that we experience, giving heart to those who face persecution by directly relating them to the Son of God.