Hebrews 2:5
For God did not place the coming inhabited world [Note: "The coming inhabited world" here probably refers to the present Christian age. It was viewed as "coming" from the perspective of Old Testament times], under the control of angels [and] that is the world we are talking about.
Hebrews 6:5
and who had experienced the good teaching of God and the powers of the coming age [i.e., they had already received some of the blessings of the Christian life, perhaps even miraculous signs].
2 Peter 3:13
But, since God has promised it, we look forward to new heavens and a new earth, where righteousness will prevail.
Revelation 11:15
Then the seventh angel sounded its trumpet, and there were loud voices in heaven saying, "The kingdom of the world has become the kingdom of our Lord [i.e., God] and of His Christ, and He will rule forever and ever."