The writer of Hebrews is presenting God’s Son as superior to all other previous methods of revelation. All of it is of God, but all of it is incomplete until Jesus brings it all together when He comes to earth. Jesus Christ is God’s final word to man. Scripture was progressively revealed to man over time, but is finished in the New Testament, never to be added to again. In that phrase, “the heir of all things,” he is telling us because Jesus is heir, He knows all and can reveal what we need to know. He also created everything, so as Creator He is above all the prophets and other means of knowing God’s word and has the authority to speak directly to us from God.
Old Testament Vs New Testament Ways God revealed/reveals Himself
How? OT “in various ways” – NT “by His Son”
When? “Many times… OT in the past” – NT “in the Last Days”
To Whom? OT “Forefathers” – NT “To Us”
By Whom? OT “The Prophets” – NT “by His Son”
Hebrews 1:1-2 God, after He spoke long ago to the fathers in the prophets in many portions and in many ways, in these last days has spoken to us in His Son, whom He appointed heir of all things, through whom also He made the world.