For Thyatira, overcoming lay in continuing to do good works and refusing the temptations that were so tantalisingly set before them. Endurance to the end is what the Lord insists on.
How will we receive power over the nations and rule them with an iron rod? Most of the old commentators agree that this means that we will be in that place of privilege when the day of judgement comes. We will be gathered out from among the people, and we will be with Christ in the judgement over the world, seeing it going under the final judgement of God. It has already been stated that he is ruler over the kings of the earth (1:5), and has made us kings and priests to his God and Father. Yet there is another sense in which we reign even now, for our prayers are heard in heaven and we reign with Christ as those prayers are answered. Little do the kings of the earth realise what great power the saints have over them. The Lord sets up and removes nations in answer to the prayers of his people. Those who seem powerful are actually disposed of for the benefit of the insignificant Christians.