I'm going to use two statements by Fred Butler as a launchpad to discuss several related issues:
I think the difference would be that dispensationalism alone doesn’t lead people to wild-eyed doctrines.
But, the defining, unifying factor is that both groups are continuationists. Meaning, they both adhere to the same view regarding the actions of the Holy Spirit in this day and age.
i) It's arguable that dispensationalism leads to date setting. Dispensationalism believes there are signs of the endgames. It believes that developments in the Mideast will be central to the fulfillment of endtime prophecies. That leads dispensationalists to correlate modern events in the Mideast with Bible prophecies about the Second Coming. And that, in turn, leads to failed, "It's the end of the world!" predictions.
Now, I don't think that's a reason to discount dispensationalism. But that's endemic to dispensationalism.
ii) Take another example: Catholics say sola Scriptura is a "blueprint for anarchy". When Catholics looks a Protestantism, they see what cessationists see when they look at the charismatic movement. It as much or more a question of what you're looking for as what you're looking at.
iii) Fred does, however, draw a valid distinction. But if anything, his distinction needs to be even more discriminating.
In the nature of the case, there are errors and abuses distinctive to continuationism. By definition, cessationism won't be prey to the same errors and abuses.
There is, however, a difference between what is distinctive to a position and what is essential to a position. For instance, there are forms of sexual misconduct distinctive to heterosexuality, viz. heterosexual fornication, adultery, rape, and incest. However, no orthodox Christian would contend that that's essential to heterosexuality.
Or to take a comparison that's closer to the issue at hand, there are errors and abuses distinctive to messianism. A messianic religion opens the door to messianic pretenders. A religion that denies messianism avoids that particular error or abuse. But, of course, Christianity is unavoidably messianic. The attendant errors and abuses go with the terrain.
Likewise, there are errors and abuses distinctive to a religions founded on prophecy and miracles. That opens the door to charlatans. A religion that denies prophecy and miracles avoids that particular error or abuse. But, again, Christianity is unavoidably committed to prophecy and miracles. The attendant errors and abuses go with the terrain.
iv) Both cessationists and continuationists must distinguish between true and false prophets, true and false miracles or miracle-workers. That's hardly a challenge unique to continuationism.
The main difference is that cessationism considers that to be more an issue in the past–although many cessationists do make allowance for modern miracles (just not modern miracle-workers).
Yet by accepting the Protestant canon, cessationists are required to distinguish between true and false revelatory claimants. So it's a difference of degree rather than kind between cessationists and continuationists.
v) Apropos (iv), three groups raise the same basic issue:
Critical scholars regard the traditional canon of Scripture (whether Tridentine, Eastern Orthodox, Oriental Orthodox, or Protestant) as an arbitrary selection. They think the cutoff between canonical and extracanonical books is ad hoc. That's because they believe both the OT and the NT contain pseudepigrapha. By the same token, they think some OT books chronologically overlap intertestamental literature while some NT books chronologically overlap some 2C literature. So, for instance, they think it's ad hoc to canonize Daniel but exclude 1 Enoch. Either canonize both or exclude both. Likewise, they think it's ad hoc to canonize Jude. 2 Peter, John, or 1 John, but exclude the Gospel of Thomas.
Likewise, Catholic apologists contend that Protestants can't justify the cutoff for their canon. And in similar vein, cessationists say continuationists can't justify the cutoff for their canon.
Of course, an obvious problem with this line of argument is when competing groups raise the same basic objection, that ricochets on their own position. Cessationists are using an argument against continuationists which Catholic apologists use against cessationists. And Catholic apologists are using an argument which critical scholars use against Catholic apologists.
Indeed, contemporary Catholic Bible scholars are critical scholars. They think Trent unwittingly canonized many books under false auspices.
vi) To be sure, cessationists deny that the Protestant canon contains pseudepigrapha. But then, continuationists say the same thing. Both groups use the same arguments in that regard.
vii) Cessationists make the apostles or their immediate successors the cutoff. However, St. Paul poses a dilemma for their position. He isn't connected to the historical Jesus the way the Twelve were. If God could raise up Paul, even though Paul wasn't a regular companion of Christ, and received crucial information, either by revelation or tradition, then the cessationist cutoff is makeshift. Conversely, if Paul is anomalous, then continuationists can draw the same line.
viii) Another problem is how their objections to continuationism and the canon have a parallel respecting the OT canon. Even if cessationists say the death of the apostles or their immediate successors demarcates the NT canon, that doesn't work for the OT canon. When cessationists say continuationists have no principled cutoff for the canon, aren't cessationists in the same situation respecting the OT canon?
By that I mean, is there an a priori objection to the production of Scripture during that 400 year interval? Sure, it's called the Interestamental period, so, by definition, that's in-between the OT and the NT. But that's a conventional designation. Is there in principle a reason to deny that God might have raised up new prophets or inspired new writings during that period? I can't think of any.
Seems to me the reason evangelicals deny it is not because that's antecedently inadmissible, but because there are no good candidates for that period. When we look at the evidence, when we look at the record, we have no reason to think God did it that way. Our conclusion is not a matter of principle, but a matter of fact.
So even if (ex hypothesi), continuationists are unable to furnish an a priori cutoff for the canon, cessationists are in the same boat. And by the same token, there can be a posteriori arguments for the closure of the canon.
ix) Mind you, it would be extremely destabilizing if God were to raise up figure like St. Paul at this late date. So that of itself might be an priori argument–which cessationists and continuationists alike could invoke.