Although the book of Hebrews was written to unbelieving Jews, Paul writes that Jesus is 'the better' <several things>. Like Peter's confession that Jesus IS the Messiah in Matthew 16:18, Jews then needed only to repent of their failure to believe that Jesus WAS the Messiah and believe He was for salvation. Paul is also writing of Gods' grace for their salvation, just as we Gentiles are saved by grace through faith.
Hebrews 4:14-16
14 Seeing then that we have a great high priest, that is passed into the heavens, Jesus the Son of God, let us hold fast our profession.
15 For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin.
16 Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need.
So where is the throne of grace? We know Jesus will be on His throne in the earthly kingdom He sets up and rules and reigns for 1000 years. Jews need only believe that Jesus is the King for entry. And after the 1000 years? I'm certainly no authority on the subject, but I think the kingdom will be taken up into the new earth and new Jerusalem for all eternity.