Remember: we are discussing pieces of evidence of overcoming: not merely future promises, but present realities found in "the one overcoming" (literal Greek). We may overcome today, we need not wait for a future event. Of course, in some sense, there will be a literal fulfillment of these promises at some time in the future. But if we are not seeing them fulfilled in us NOW, at least to some degree, then we are not overcoming. Overcomers are overcoming TODAY, so if we are not overcoming then we are missing out on the present reality as well as the future promise.
These verses are rich, but I would like to especially focus on one thing: "To him will I give power over the nations." The language of this passage is identical to Psalm 2. The Father has said that the Son will rule the nations, and now the Son says the Overcomers will rule with Him. What a glorious thing to rule with Christ! But this certainly sounds like a future promise. How could we claim to have power over the nations today?
The secret is found in Matthew 6:10. Jesus says our daily prayers are to include, "Your Kingdom come, Your Will be done: as in Heaven, so in Earth." This is a revolutionary act. It is praying for the establishment of a Kingdom and a Will in which Christ has the preeminence as All in All. In this Kingdom, there is no room for any earthly government, ruler, or king. In this Will, there is no room for any human agenda. We know Jesus is Lord, yet we do not see all things submitted to Him (Hebrews 2:8b). So what do we do in the meantime? Overcomers do not just passively wait for Jesus to come back. They pray for His Kingdom to be established not only in their personal lives, but the lives of new converts, and for His Will to be performed by that individual through the exercising of their spiritual gifting. In this way, they exercise power over the nations by preparing the way of the Lord. How? By raising up valleys, bringing down mountains, making the crooked things straight, and making the rough ways smooth (Luke 3:5,6), by being salt and light in the communities in which they live. So this prayer is destructive in a natural sense, but constructive in a spiritual sense, for as the nations (local communities) are decreased, Christ is increased (cf. John 3:30).
Just as Jeremiah was set over nations and kingdoms "to root out, and to pull down, and to destroy, and to throw down, to build, and to plant" (Jeremiah 1:10), so we have received this authority also. We do not serve in a governmental capacity, but in a spiritual capacity, praying for the Kingdom and Will of God to come forth. Such prayer is very weighty and universal. It is beyond the earth, and so it moves the earth. In addition to the authority over the nations, we are given "the morning star". Christ is the Morning Star (Revelation 22:16b), the Heavenly Man, Who is higher than the nations and kingdoms of this world. The Morning Star gives Overcomers the heavenly authority which is beyond the influence of the earthly realm in which they must live.