At times throughout the history of the Church, some Christians have held to the belief that the Church ought to aspire to political power in order to fulfill the commands of Jesus, such as the Great Commission (cf. Matthew 28:18-20). This position has occasionally been known as Christian dominionism, because it seeks to achieve earthly dominion for Christianity. Dominionists sometimes cite passages such as Matthew 6:9-13, in which Jesus encourages His disciples to pray that the Father's kingdom would come, and that His will would be done on earth as it is in heaven, and John 14:12, in which Jesus states, "Truly, truly, I say to you, he who believes in Me, the works that I do, he will do also; and greater works than these he will do; because I go to the Father" (NASB). However, is this really what Jesus had in mind when He made these statements? Did Jesus really command Christians to aspire to and acquire public and political positions of power?
As we've just observed, Jesus certainly did teach His disciples to pray that the Father's kingdom would come, and that His will would be done on earth as it is in heaven. However, what Christian dominionists typically fail to appreciate is that Christ's heavenly, spiritual kingdom should not be conflated with any earthly, political sort of kingdom. In fact, Jesus implicitly emphasized this point when, just before His crucifixion, He answered Pontius Pilate, saying that, "My kingdom is not of this world. If My kingdom were of this world, then My servants would be fighting so that I would not be handed over to the Jews; but as it is, My kingdom is not of this realm" (John 18:36, NASB). In other words, although the fulfillment of the Great Commission certainly does not preclude Christians from holding political power, it certainly does not require them to, either.
In fact, the Great Commission itself gives us a good idea of what Jesus had in mind for His priorities for His Church. In Matthew 28:18-20, we read Jesus' commands: "All authority has been given to Me in heaven and on earth. Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit, teaching them to observe all that I commanded you; and lo, I am with you always, even to the end of the age" (NASB). Now clearly, the substance of this command is to "make disciples," something which describes the spiritual reality of a person who ceases to be an enemy of God and becomes instead one of His children. The principle implicitly reflected in Jesus' reply to Pontius Pilate is that such a spiritual victory can only be accomplished by means of a spiritual kingdom: Jesus' rule over our hearts is not one of external coercion, as a political power would have, but one of internal compulsion, as only the convicting work of the Holy Spirit can produce. Indeed, such a spiritual victory would seem to be the only kind of victory that matters, for any other kind of victory would fall short of restoring fallen people to the glory of God.
Thus, we see that Jesus assumed no political position, not because this was a work which was too great for Him, but because it was too small: a political position could, at best, correct only the externally problematic aspects of humanity, without ultimately resolving their internal sin natures. One day Jesus will rule, both externally and internally, but for now, His kingdom reign is mostly limited to a spiritual reality. Even Jesus' miracles, like political power, could only fix temporal problems: Lazarus, for instance, although he was raised from the dead (cf. John 11), eventually died again. On the other hand, the greater works that you and I have been called to participate in are eternal in nature, and are precisely what Jesus has called us to in the Great Commission: we are to participate in bringing about the spiritual victory, rule, and sovereignty of Christ to its full effect in the hearts of the lost. The quest for Christian political power is thus risks ultimately becoming an ill-fated grab at a superficial solution to a fundamental human problem, and only the spiritual kingdom of Christ can truly set us free.
Of course, this doesn't mean that the kingdom of God is only spiritual: the point is simply that identifying the kingdom of God with political power is a mistake. But the kingdom of God nevertheless has plenty of earthly effects as well, whose significance ought not to be minimized. In fact, if the kingdom of God were only a spiritual reality (i.e., completely irrelevant to our everyday life), then it would not truly represent God's sovereign rule over all things.
The kingdom of God in fact entails many "real world" implications (although I hesitate to use the term "real" in this context, since there is nothing less real about the spiritual realm), such as victory over sin and temptation, the ability to walk in holiness and be filled with the Spirit, and sometimes even manifestation of a miraculous provision of healing, wisdom, or some other blessing from the Lord. The salvation and sanctification of lost souls is certainly the overwhelming focus of the New Testament, but this doesn't preclude God's miraculous intervention on behalf of His church as He pleases. The kingdom of God is also manifested as the Christian/scriptural worldview is brought to bear by the church on every aspect of fallen humanity; because the Christian worldview is a total picture of reality, it influences every aspect of God's creation. This means there is a Biblically distinctive way of looking at things like government, philosophy, physics, music, art, craftsmanship, and so much more.
So, in short, the kingdom of God is not limited to the spiritual realm or only the saving of souls. On the other hand, although the Great Commission is of course not referenced in John 14:12, there are good reasons to think Jesus had something more like this in mind than miracles when He said that we would do greater works than Him. For one, it is hard to imagine superseding the miracles that Jesus did, which included reading the mind of the Samaritan woman (cf. John 4), raising Lazarus from the dead (cf. John 11), miraculously feeding of thousands on multiple occasions (e.g., Mark 6:33-44), and innumerable healings, just to name a few. Moreover, Scripture itself tells us that not every believer will have the gift of miracles or healings (cf. 1 Corinthians 12:28-31), but John 14:12 is clearly directed toward all believers. So miracles almost certainly cannot be what Jesus has in mind here.
Although the text itself gives us few clues about exactly what Jesus has in mind, we can be sure that it is something which applies to all believers, and it is reasonable to infer that this may be summed up in what we now know as the Great Commission, described in Matthew 28. This is greater than the works which Jesus did, for several reasons. First, Jesus' earthly miracles, as I pointed out before, only resolved earthly, human problems of a temporal nature, whereas the fulfillment of the Great Commission resolves the problem of sin, which has eternal consequences. Second, Jesus' earthly ministry was limited to a particular time in history and a particular geographical region, while the church and its expansion are unlimited in extent and effect. This enables the community of believers, and even individual believers within that community, to accomplish works with a greater impact than Jesus' own earthly works. This isn't the only way of understanding John 14:12, but I think this is the most plausible option.
In summary, the Biblical texts sometimes cited in support of Biblical dominionism, upon examination, really do not require Christians to pursue public office, even though this is still certainly permissible. Rather, great care must be taken that the quest for political power does not attempt to supplant the work of the Holy Spirit through the Church. Political influence will always provide at best a temporary, external solution to a fundamental, internal problem of the human heart which can only be solved by Christ.