The letter to the Hebrews is an impassionate plea that the readers, who were predominately Jewish converts, must not turn away from Christ and return to their former ways (i.e. Judaism or paganism). The author does so by arguing for the superiority of Jesus Christ, as God’s exalted Son, final revelation, eternal priest, and perfect sacrifice.
In spite of intense persecution, these followers of Jesus should follow the great models of faith in the past and remain faithful to Jesus. Thus, one of the most important contributions of Hebrews is its balance of continuity and advance in relating the OT and NT to each other.