The majority of the ECFs were not Premil. Where do you get this from?
Do you believe in biblical corroboration?
that just shows how much you actually havent studied this...
In as many days as this world was made, in so many thousand years will it be concluded. . . . For the day of the Lord is as a thousand years. In six days created things were completed. It is evident, therefore, that they will come to an end at the sixth thousand year. Irenaeus (c. 180, E/W), 1.557.
The days will come in which vines having ten thousand branches will grow. In each branch, there will be ten thousand twigs, and in each shoot there will be ten thousand clusters. Each cluster will have ten thousand grapes, and every grape will give twenty-five metretes of wine, when pressed. . . . In like manner, a grain of wheat will produce ten thousand ears. Irenaeus, citing Papias (c. 120, E), 1.153, 154.
Among these things, Papias says that there will be a millennium after the resurrection from the dead, when the personal reign of Christ will be established on this earth. Eusebius, citing Papias (c. 120, E), 1.154.
I and others who are right-minded Christians on all points are assured that there will be a resurrection of the dead, and a thousand years in Jerusalem, which will then be built. . . . For Isaiah spoke in that manner concerning this period of a thousand years. Justin Martyr (c. 160, E), 1.239.
There was a certain man with us, whose name was John, one of the apostles of Christ, who prophesied by a revelation that was made to him, that those who believed in our Christ would dwell a thousand years in Jerusalem. Justin Martyr (c. 160, E), 1.240.
The Sabbath is the type and symbol of the future kingdom of the saints, when they shall reign with Christ after He comes from heaven, as John says in his Revelation. For “a day with the Lord is as a thousand years.” Hippolytus (c. 205, W), 5.179.
We do confess that a kingdom is promised to us upon the earth, although before heaven. Only, it will be in another state of existence. For it will be after the resurrection for a thousand years in the divinely-built city of Jerusalem “let down from heaven.” Tertullian (c. 207, W), 3.342.
The Amen sends flames on the nations. And the Medes and Persians burn for a thousand years, as the apocalyptic words of John declare. After a thousand years, they will be delivered over to Gehenna. And he whose work they were is burned up with them. Commodianus (c. 240, W), 4.211.
The true Sabbath will be in the seventh millennium of years, when Christ will reign with His elect. Victorinus (c. 280, W), 7.342.
Taking my journey and going forth from the Egypt of this life, I came first to the resurrection, which is the true Feast of the Tabernacles. There, I set up my tabernacle, adorned with the fruits of virtue, on the first day of the resurrection, which is the Day of Judgment. And I celebrate with Christ the millennium of rest, which is called the seventh day, even the true Sabbath. Methodius (c. 290, E), 6.347.
The dead will rise again . . . to reign with God for a thousand years. Lactantius (c. 304–313, W), 7.218.
and when it concerns Eusebius, those are direct quotes from his own writings...
You know, for someone like you to make a claim about the early church fathers and yet have absolutely no idea about what they taught, I don't think you have any authority to say what the early church did and did not believe