https://petergoeman.com/what-is-dispensationalism-a-concise-explanation/
There are many things people accuse dispensationalists of that are not inherent to the system of dispensationalism. In this brief article, I want to look at which beliefs define dispensationalism specifically. In other words, what must each and every dispensationalist believe in order to be a dispensationalist?

We can define dispensationalism broadly as a set of doctrinal beliefs that stem from a specific hermeneutical viewpoint. Dispensational ideas primarily concern hermeneutics, ecclesiology, and eschatology. This means that within those three spheres, a dispensationalist must hold to a specific set of beliefs concerning how one understands Scripture, the role and function of the church, and the end times. Even within these areas, there is room for disagreement. In what follows are the four essential beliefs that each dispensationalist must hold to.
Dispensationalism teaches that the Old Testament must be interpreted within its own context.
This is, in my opinion, the most important belief of a dispensationalist because it leads to the rest. The core teaching of dispensationalism is that the Old Testament must be interpreted according to its own context, and the New Testament cannot reinterpret or change the meaning of a passage. In other words, one does not need the New Testament in order to know the true meaning of an Old Testament passage. The New Testament is crucial to our understanding of the unfolding revelation of God, but a dispensationalist is adamant that the New Testament does not reinterpret the Old.
Dispensationalism teaches that there is a distinction between Israel and the Church.
Stemming from the previous point, a dispensationalist believes that the Bible clearly demarcates Israel and the church as distinct entities. Dispensationalist teachers typically will clarify that this does not mean there is no relationship between Israel and the church. In fact, both can rightly be described as the “seed of Abraham.” However, similar to how complementarians say that men and women are equal in value, yet have different functional roles; so also a dispensationalist will say there is a functional difference in God’s plan between ethnic Israel and the church as described by Scripture.
Dispensationalism teaches that there is a future for ethnic Israel.
Again, this point is linked with the previous two. Because the Old Testament speaks of a future for ethnic Israel (cf. Lev 26:40–45; Deut 4:25–31; Hos 3:4–5; Zech 12–14, etc.), a dispensationalist reads the New Testament as an affirmation of those promises of restoration (cf. Matt 19:28; Acts 1:6; 3:19–21; Rom 11:25–26, etc.). Most people have heard the hackneyed (yet important) dispensational phrase that goes something like this: we cannot assume the curses for disobedience applied to Israel, but the promised blessings for repentance and obedience do not.
Dispensationalism teaches that the promises made to ethnic Israel will have an actual, future fulfillment in the Millennial Kingdom.
This point naturally flows from the previous points and becomes a good summary of what a dispensationalist believes. When a dispensationalist reads the Old and New Testaments, he sees that God made many promises to Israel. These promises include a return to the land (Lev 26:40–45; Deut 4:25–31, etc.), a promised ruler who will rule over Israel (Ezek 34:23–24), and prominence among the nations (Isa 2:2–4). These promises either will be fulfilled, or they won’t be. A key point in defining dispensationalism is that a dispensationalist looks for literal fulfillment of what was promised to Israel.
A dispensationalist also teaches a thousand-year millennium, because that is the time period within which God is to fulfill His promises to His chosen people, Israel. Mistakenly, dispensationalism is often accused of basing its doctrine of the millennium on one passage of Scripture (Rev 20). However, I’m not alone when I say that I’m a premillennialist before I get out of the Old Testament.
The prophets, in particular, convince me that there must be a future for Israel, and God’s promises to Israel must also be fulfilled. I am looking for the content of the millennium before I move on to the New Testament. It is the New Testament that confirms what the Old Testament already laid out. Furthermore, it is the New Testament that provides the time frame for understanding when the prophecies of the Old Testament will be fulfilled (Rev 20).
Concluding Thoughts
My list may be minimalist to some, but these are the key issues, as I see them, regarding what makes a dispensationalist. A dispensationalist can hold to a wide variety of beliefs that are not inherent to dispensationalism as a system, but I cannot see how one could be a dispensationalist and not hold to these key components.
Addendum: Other Lists of the Essentials of Dispensationalism
Here are some other lists of essential beliefs of the dispensationalist, provided by Vlach in his book on Dispensationalism (highly recommended):
Essentials of Dispensationalism by Charles Ryrie (1965):
- A distinction between Israel and the church.
- Literal interpretation to all Scripture, including prophecy.
- The underlying purpose of God in the word is the glory of God.
Essentials of Dispensationalism by John Feinberg (1988):
- Belief that the Bible refers to multiple sense of terms like “Jew” and “seed of Abraham.”
- An approach to hermeneutics that emphasizes that the Old Testament be taken on its own terms and not reinterpreted in light of the New Testament.
- Belief that Old Testament promises will be fulfilled with national Israel.
- Belief in a distinctive future for ethnic Israel.
- Belief that the church is a distinctive organism.
- A philosophy of history that emphasizes not just soteriological and spiritual issues, but social, economic, and political issues as well.
Common Features of Dispensationalism by Blaising and Bock (1993):
- The authority of Scripture.
- Dispensations.
- Uniqueness of the church.
- Practical significance of the universal church.
- Significance of biblical prophecy.
- Futurist premillennialism.
- Imminent return of Christ.
- A national future for Israel.
Essentials of Dispensationalism by Mike Vlach (2017):
- The primary meaning of any Bible passage is found in that passage. The New Testament does not reinterpret or transcend Old Testament passages in a way that overrides or cancels the original authorial intent of the Old Testament writers.
- Types exist but national Israel is not an inferior type that is superseded by the church.
- Israel and the church are distinct; thus, the church cannot be identified as the new and/or true Israel.
- Spiritual unity in salvation between Jews and Gentiles is compatible with a future functional role for Israel as a nation.
- The nation Israel will be both saved and restored with a unique functional role in a future earthly millennial kingdom.
- There are multiple senses of “seed of Abraham,” thus the church’s identification as “seed of Abraham” does not cancel God’s promises to the believing Jewish “seed of Abraham.”