As Paul speaks to a Hebrew audience, he begins to tell them about who Jesus is. To understand the book of Hebrews, we first need to understand the Old Testament and the history of the Jewish people. 

Jesus came to earth as a human and fulfilled the Old Testament prophecies. Despite his supremacy, he offered his own life as a sacrifice for ours. We all must choose whether to accept God's love and sacrifice, or to ignore it.

Paul explains Jesus' humanity, which was hard to grasp for the Greek-thinking culture he was writing to. Jesus' humanity is important because through his humanity he can atone for our sins, display his humility, and understand the struggles of humanity on a personal level. 

While a hardened heart does not affect the Christian believer's salvation, it may cause them to miss out on God's gifts and joy. Hebrews 3 lists five ways to soften our hearts to God.