I'm not asking as a Preterist. I disagree with them as strongly as I disagree with dispensationalists and pre, mid, post, ah= millennialists as far as the scripture is concerned. But I have never seen someone cite anything other than what they believe to tag them as "heretics." So it is something I have been curious about for decades.
Here's why, and your question proves that the following is the case to this very day.
The Nicene Creed becomes state law.
The Roman Emperor Theodosius I's Edict of Thessalonica in 380 CE did not make all forms of Christian practice illegal, but it condemned and outlawed all forms of Christianity that did not conform to Nicene Christianity. This had severe consequences for Christian groups considered heretical, particularly Arianism.
Background: The Arian controversy
The Edict of Thessalonica came during decades of intense theological dispute in the Roman Empire known as the Arian controversy.
Arianism: Led by Arius, a priest from Alexandria, this school of thought argued that Jesus Christ was not co-eternal with God the Father but was a created being, subordinate to him.
Nicene Christianity: This orthodox position held that Christ was consubstantial, or of the same divine substance, as the Father. This was first established at the First Council of Nicaea in 325 CE.
The controversy was deeply political and religious, with different emperors and regions supporting opposing viewpoints. Emperor Theodosius's predecessor, Valens, was an Arian, which had allowed Arianism to flourish in the East.
The Edict's prohibitions
With the Edict of Thessalonica, Emperor Theodosius I formally mandated adherence to Nicene Christianity throughout the Roman Empire and designated all other Christian interpretations as heresy.
Specifically, the edict declared:
Marginalization of heretics: The law branded non-Nicene Christians as "foolish madmen" and decreed that their places of worship could not be called "churches".
Exclusion from cities: Later decrees, beginning in 381 CE, forbade heretics from meeting for worship within city walls, effectively banishing them from urban centers and their social and religious life.
Confiscation of property: The state began seizing the property of heretical Christian groups, including their churches, and turned them over to Nicene bishops.
State-sanctioned punishment: Theodosius's edicts authorized imperial authority to punish those who deviated from Nicene doctrine. While early punishments were non-lethal, the legal basis was established for later, more severe persecution. In 385, the bishop Priscillian became the first Christian to be judicially executed for heresy, though the sentence was condemned by some prominent bishops.
The aftermath
The Edict of Thessalonica effectively ended the Arian controversy by using imperial power to crush theological dissent. Theodosius's actions, and the subsequent First Council of Constantinople in 381 CE,
ensured that the state and church would enforce a single, orthodox interpretation of Christianity. All other Christian groups, no matter how large their following, were cast as illegal and dangerous enemies of both the church and the state.
Whereas, all the prophecies, all the promises and all the grammar point to a first century fulfillment, futurism has it narrowed down to eternity.
Jesus said in the book of Revelation He was coming quickly using the present tense 4 times. I guess believing Him is considered a damnable heresy. Well, I'm going to believe Him anyways.