This doctrine is reserved the Section on “Ethics,” however, I will briefly define it here for context.
I am using the term as Vincent Cheung as defined it, since his term properly encompass what I also believe the Scripture teaches on this subject. He was the first to use it, and it is a clear definition, thus I will use his.
I will let him define it here:
Expansionism is the Bible’s explicit doctrine on the subject of spiritual gifts, powers, and miracles. This is the only biblical perspective. I am unaware of any official recognition of the doctrine, so I have selected the term for it. The word is sometimes used in a political sense, but I mean it in a spiritual sense. It is applied to every aspect of the advance of the gospel, but in this context we will focus on the supernatural powers and miracles that God works in association with his people. This is the biblical doctrine that supernatural powers and miracles are to increase in God’s people beyond what Jesus Christ himself exercised. They are to multiply exponentially in quantity and frequency, in intensity and magnitude, in the diversity of representation, and in the scope of jurisdiction. There should be an accumulated momentum, so that compared to Jesus and the apostles, and compared to each previous generation, the church should demonstrate more miracles, greater miracles, miracles performed by more kinds of people, and miracles performed in more areas of the world…
Jesus would perform a miracle, and then he would say that the one who has faith can perform the same miracle, and even a greater miracle — a greater miracle than the one he did. It was as if he wanted to erase every doubt and condemn every excuse. He emphasized this doctrine again and again, and he formulated it in explicit terms. He referred to his miracles (John 14:11), and then he said, “I tell you the truth, anyone who has faith in me will do what I have been doing. He will do even greater things than these, because I am going to the Father” (14:12). This leaves no room for cessationism, but it is much more than continuationism. It is expansionism.
The Bible contains statements that promise us the ability to perform specific kinds of miracles by faith. For example, James 5:15 is a promise for miracles of healing. In fact, it is a command to perform miracles of healing as much as it is a promise. However, even before we learn about these promises, or even without them, John 14:12 guarantees the continuation and expansion of the miracles that Jesus performed. Even without Matthew 17:20, Matthew 21:21, Mark 11:23, and every other passage like these, the one who has faith possesses an irrefutable and permanent basis to perform the same kinds of miracles, such as to command a sickness to leave someone, or to command the restoration of a damaged or missing organ. John 14:12 encompasses all the miracles of Christ, so that miracles of prophecy, miracles of nature, and all other miracles, are also included and promised to those who have faith. That said, we indeed have Matthew 17:20, Matthew 21:21, Mark 11:23, and many other passages that dictate the doctrine of expansionism. It is inescapable….
… Before Christ ascended to the throne of God, he declared that the Holy Spirit would come upon the disciples, and they would receive the same power that he exercised in his ministry (Acts 1:8). Keep in mind that he had already promised that anyone could perform the same and even greater miracles by faith, and the disciples had already been performing miracles by faith, healing the sick and casting out demons in his name. Jesus did not want this to merely continue. He wanted more, much more. This would add still another dimension of spiritual power to their lives — faith upon faith, power upon power. Jesus was not satisfied until his followers had attained an excessive and ridiculous level of charismatic endowments. He refused to accept a mere continuation of his ministry, but he demanded an expansion, an escalation. He wanted the power they demonstrate to be outright absurd. He told them not to leave the city until the Spirit arrived. Then they were to expand, and carry this power “to the ends of the earth.”
When we come to the events after the ascension of Christ, we need to move quickly, because too many things happened for us to consider them in detail. The disciples were no longer just talking about it, but they were doing it. Expansion in every aspect was happening — the quantity of the miracles, the quality of the miracles, the diversity of believers, and the immensity of territories. There was an explosion of supernatural power, and miracles splattered all over the place.
On the day of Pentecost, the Holy Spirit arrived in a spectacular fashion upon the group of believers. Only ten percent of them were apostles (Acts 1:15), but all of them were directly infused with the same power to receive revelations and to perform miracles that infused Jesus Christ (Luke 4:14, 24:49, Acts 1:8, 2:4). Since the first day, the overwhelming majority of those who had prophetic gifts and miraculous powers were not apostles. Peter explained that it was exactly what was supposed to happen. He referred to the prophet Joel: “In the last days, God says, I will pour out my Spirit on all people. Your sons and daughters will prophesy, your young men will see visions, your old men will dream dreams. Even on my servants, both men and women, I will pour out my Spirit in those days, and they will prophesy” (Acts 2:17-18). The anointing of the Spirit had spread beyond a few kings and prophets, to Christ and his disciples, and now it would expand in power and scope to all kinds of people, penetrate all levels of society, invade all areas of the world, for all times in the future….
Let me give a quick summary of this.
Expansionism is thus, the combination of the (1) discipleship “faith” Jesus mentions in “…whoever believes in Me will do the works I have been doing, and they will do even greater things than these,” John 14:12 (NIV). This basic discipleship faith is meant for all disciples of Christ. First it says, “whoever believes in Me,” and the context is paralleled with loving each other—or is loving our Christian brothers only for the 12 original apostles? (2) The combination of “baptism of the Spirit” that Jesus commanded, and Peter through the Joel prophecy, says it for all whom God calls to Himself in salvation. (3) The combination of the “gifts of the Spirit” as mentioned briefly in Corinthians 12-14.
There is even more, such as what some call the mode of the “anointing presence of God,”(etc.) but we will just keep it to 3 for simplicity.
These 3 combinations are not meant as static; rather, they are meant as an ever increasing expansion in and through the Church to bring the Kingdom of God on earth. That is, the millennium started when Jesus sat on His throne, at the right hand of the Power. He commands the ever increasing expansion of His kingdom on earth by commanding all to repent (baptism of faith), to be empowered (baptism of the Spirit). By these two baptisms, the chosen elect are to be filled with intellectual, ethical and missional power to expand His kingdom on earth, like the Israelites expanded into the Promise Land. This expansion will continue until the fullness of the gentiles are complete and the Jews experience an accelerated repentance in Jesus Christ.
This is what postmillennialism is missing; it has the structure without the content. It has the building but no people. It has a body but no soul. Since for about 1500 years the church has labeled expansionism as a heresy, then no classical doctrine of eschatology is able to be salvaged by combining it with expansionism and still calling it by its classical name, since the classical name contradicts expansionism.
Because expansionism is the correct application of eschatology, then one can simply term expansionism, as Biblical Eschatology and it would be sufficient. However, for this book I will term the whole meaning of eschatology as “Right-Hand-of-the-Power-ology.” Or for short, Throneism, or Powerism. I would rather use these words, because the doctrine of expansionism, is a consequent of the antecedent, of Jesus as He sits at the right hand of the Power, and from this position, commanding and giving us His power to expand. Depending on, if one defines Jesus sitting at God’s right hand as much as a definition as what the church does, by expanding in power, faith, and miracles, then expansionism can be used as a complete term for biblical Eschatology.
Also, from this doctrine of expansionism, we can throw the entire various definitions of cessationism into the garbage as blasphemy and rebellions against God. When all definitions fall horrifically short, it does not matter the version of it. Thus, when I rebuke cessationism, I am lumping all of them together, (ranging from those who say “all miracles and gifts have stopped,” to those who say “the gifts have mostly stopped, some miracles still might happen when we ask”), as heretics and deserving of judgment. It does not matter if one arrow was 50 miles from the bullseye and the other 56 miles, and another was 59 miles. All are completely and ridiculous failures. At least with modern day Pentecostals and Charismatics their arrow was only 30 feet from the bullseye. Still, to miss the target that far off is embarrassing, yet, there is a significant difference of 30 feet compared to 50 miles. The cessationist were not even trying to aim for the Scripture.
 Vincent Cheung. “Expansionism: A Gospel Manifesto.”
From the ebook, Fulcrum. 2017. Ch. 1. Pg.5-11.
I quoted this at large, because I wanted to make sure there was plenty of context for Vincent to define this doctrine in his own words, thus, if I were to teach something different or disagree there is ample context to demonstrate.
 Compare this to John 3:16.
“…whoever believes in him shall not perish but have eternal life.”
John 3:16 (NIV)
“…whoever believes in Me will do the works I have been doing, and they will do even greater things than these.”
John 14:12 (NIV)
 Some might recognize the Smith Wigglesworth book title, Ever Increasing Faith. Thus, it is not as if Vincent was 100% original in this, but that his definition is a fuller definition, in addition to being concise and clear