This is a significant statement in Daniel which is confirmed in the NT.We know that the saints of God will reign with Christ for 1,000 years (Rev 20).
But according to everything revealed about the Church, it would also appear that the saints will be delegated authority and rule for eternity, and the degree of authority will be governed by the amount of suffering endured on earth.
And hath put all things under his feet, and gave him to be the head over all things to the church, Which is his body, the fulness of him that filleth all in all. (Eph 1:22,23)
"And hath put all things under his feet" refers to the eternal power, authority and rule of Christ for eternity as revealed in this passage:Far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come (v 21)
In this context, the Church is called "the fulness of Him that filleth all in all". Which means that the authority of Christ over all creation will be extended through the Church, which is the saints of God, and is explained further in these verses: To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God, According to the eternal purpose which he purposed in Christ Jesus our Lord: (Eph 2:10,11)
The principalities and powers are the hierarchies of angelic beings (both good and bad) in the heavenlies (with only the holy angels in God's Heaven). Even though angels are far more powerful than humans, they are not the saints of God, but ministering spirits for the saints. So they will know through the Church that God has delegated His authority, which was already given fully to Christ, further through the saints of the most High.
It would appear that just as an earthly ruler delegates authority through provincial and local governors and governments, Christ will make His saints -- selectively -- rulers and governors, and possibly throughout the universe. As we know from several parables, the degree of responsibility will be determined by the faithfulness of Christians on earth, with the twelve apostles receiving twelve thrones in order to judge the twelve tribes of Israel.
So Christians who were lazy, or irresponsible, or lackadaisical, or misleading others on earth will be given little or no responsibility (an aspect of rewards), whereas those who endured, suffered, or were martyred will be given great responsibilities for eternity. We will not be sitting around on clouds, strumming harps, as some vainly imagine.