It is foolish for anyone to try to predict Christ’s return. Regardless, there is no conflict between these verses...it is the nature of the lost to know what God promises but that they will scoff anyway.
Matthew 24:36 “But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only.”... .44 Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.
2 Peter 3:3 “Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
The Millenium is a spiritual reign of Christ that has been present in the community of Christ since Pentecost.
The Bible continually uses the terms Kingdom of God, Kingdom of heaven, Messianic Kingdom and Church interchangeably
The entire bible is amillenial and the Rapturists can only distort Revelation 20:1-6 -- note "distort" to put their 19th century rapture philosophy
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Yet we need to read what the Apostles themselves were taught and what they believed
Notice that they state that the Apostles and their listeneres were in the last days or the end of the age -- because the Messiah had come
Peter never changed his mind about this - as we read in 1 Pet 1:20 Christ was destined before the foundation of the world but was made manifest at the end of the times for your sake
This is relected in Pauline epistles like 2 Tim 3:1 "In these last days" and Jude 18 How that they told you there should be mockers in the last time, who should walk after their own ungodly lusts.
We have been in the last days since that first advent of Christ
Since the Ascension God's plan has entered into its fulfillment. WE are already at 'the last hour'. Already the final age of the world is with us, and the renewal of the world is irrevocably under way