Thank you for the interpretative question on Hebrews 2:5, “In Hebrews 2:5, what is “the world (οἰκουμένη) to come?”
I want to commend you for the precise observation of the Greek word, oikoumene, which is translated in English as being world.
In the Greek, the word, world, is more precise than in English. In the Greek, the word, world can be translated as cosmos, an age or time periods, or the inhabited earth/the people of this world.
As one rightly noted that the word is oikoumene which refers more so to the inhabitants of earth. As I observe the context and text, earth was not made for the angels. Earth was made for man. The angels are messengers of God to the inhabitants of the earth and guardians to help those being saved to inherit salvation.
Hebrews 1:8 says this, “Are not all angels ministering spirits sent to serve those who will inherit salvation?” (NIV).
Hebrews 2:1–4 affirms this by saying, “We must pay the most careful attention, therefore, to what we have heard, so that we do not drift away. 2 For since the message spoken through angels was binding, and every violation and disobedience received its just punishment, 3 how shall we escape if we ignore so great a salvation? This salvation, which was first announced by the Lord, was confirmed to us by those who heard him. 4 God also testified to it by signs, wonders and various miracles, and by gifts of the Holy Spirit distributed according to his will” (NIV).
The author of Hebrews continue in his writing that the Son has a superior place over the angels and that he is even before all mankind. The Son of God although lower than the angels for a brief moment in time will be exalted above heavenly creatures and earthly creatures. The world that is to come referring to the millennial kingdom in which the Son will reign as King of Kings and Lord of Lords. Everything will be subject to him (vs. 8). In other words, the person that the writer of Hebrew is referring is to the Son who will exalted above all things in which everything is subject to him. It is the coming inhabitants of earth, which I interpret it to be the kingdom people who are redeemed in which he is unashamed to call the inhabitants his family or brothers (vs. 10–11. Believers are children of God. The Son of God will acknowledge that we are children of God. What an honor that is for those who believe, to be recognize by the Son of God. As redeemed people, they will be in subjection to him on earth as he is the King and Lord over all.
There is the implication of a inhabitant people to live in a new coming world, the New Heaven and the New Earth. The writer continues in his presentation that Moses was a faithful servant over the the earthly house of God while Jesus is the Son over the heavenly house of God (Hebrew 3).
SUMMARY: God created the world for the kingdom people of this coming world where the Son will reign over this world.
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