It is important to keep in mind while reading the epistle to the Hebrews that its original recipients were Jewish people who had professed faith in Jesus Christ as their Lord and Savior. The author of Hebrews wrote to them because they were in danger of denying their faith in Christ and returning to life and faith under the Old Covenant. The Old Covenant was not only made obsolete but had been replaced by the New Covenant of which Jesus is the Mediator. Therefore, to return to the Old Covenant was to return to a sacrificial system under which one could not be forgiven of his sins and have eternal life. Only the sacrifice of Christ, Whose blood they were in danger of counting a common thing (10:29), could finally and forever put away sin (9:26).
In Hebrews 1:4-14, the writer attempts to convince them to continue under the New Covenant by arguing that Jesus the Mediator of the New Covenant is better than the angels who helped mediate the Old Covenant. To stress the seriousness of returning to the Old Covenant, he reminds them that disobedience to the word spoken through angels (the law of Moses) received a just punishment (2:1-4). Of how much greater punishment were they worthy if they disobeyed the word spoken by Jesus, God’s Son Who is far superior to the angels? We too are encouraged, even warned to continue in our faith which is in Jesus Christ to the end.