The Sheep And The Goats

Jesus says that at his coming with angels, he will divide the righteous and the wicked he finds, putting the sheep (the righteous) on his right and the goats (the wicked) on his left (Matthew 25:31-46).  The righteous are granted entrance to a kingdom of God, while the wicked depart from Christ into the hellfire he says was prepared for the devil and his own angels.  This did not happen in the gospels or the book of Acts before his ascension, so it would have to take place at his return.  His words about the sheep and goats are not the only place where Jesus talks about his then and still-future coming as having angels.  Matthew 24:30-31 also says that the Son of Man's coming will involve angels gathering God's people from one end of the heavens to the other.  That angels are with him at his coming, which is visible and bodily unlike what the delusions of preterism hold (Acts 1:7-11), is attested to even by some parables of Christ.

Matthew 13:37-43 addresses what Jesus means by the parable of the weeds (13:24-30).  In this narrative, weeds are allowed to grow with wheat until the harvest, when they are separated and burned.  In the clarification provided by Jesus, the field where the seeds are sown is the world, the harvest is the end of the age, and so on.  Jesus says here that angels are represented by the harvesters in this story and that at the end of the age, these beings will bring sinners to the furnace, paralleling how he says in Matthew 25 that the wicked alive at his return will be sent to hell to perish (John 3:16)—for these people, hell is not an afterlife because they do not die beforehand, and even aside from many other verses, it is clear from Matthew 25:46 that eternal punishment is contrasted with eternal life.  Any alternative to eternal life entails by necessity that someone does not live forever, and thus the wicked do not exist forever.  

The much shorter parable of the net in Matthew 13:47-48 is also immediately given the same kind of explanation for that of the weeds in the following two verses.  Here, Jesus again teaches that angels will separate the wicked from the righteous and put them in the fire at the end of the age as the fishermen of the parable divide good and bad fish from their net.  Also of note given the errors of preterism is that Jesus is saying these things both to clarify symbolic stories and outside the context of Revelation, which means that any genuinely figurative descriptions in Revelation would still not mean he is not being literal.  Thus, Jesus is not speaking figuratively when he explains; he is clarifying what his figurative stories about weeds and a net literally mean.

The separation of sheep and goats happens literally at the Second Coming, as certain aforementioned parables of Jesus in Matthew as well as his direct teaching on the separation from chapter 25 establish.  This prophecy could not have happened non-visibly and non-literally back in 70 AD for many reasons, among them how Jesus never ushered in an actual lasting kingdom on Earth after that time as predicted (Matthew 13:43, 25:34).  Revelation 20:1-6 combined with 1 Thessalonians 4:13-18 presents the first resurrection, that of the righteous (mentioned together with that of the wicked in Daniel 12:2), as occuring when a rider on a white horse called the Word of God (not said to be a Jesus in Revelation 19:13, but affirmed in John 1:1-4, 14) comes to defeat the beast and his army, which is in turn succeeded by a thousand year kingdom of Christ that continues in New Jerusalem when heaven comes to Earth (Revelation 21-22).  Resurrection and other such things did not happen in 70 AD!

The separation of the sheep and goats is not the final judgment of Revelation 20:11-15.  It cannot be, since the bodily resurrection of the wicked happens before the judgment of the great white throne, whereas Jesus says the sheep and goats are divided right at his coming.  For the goats, the lake of fire is their destination, yet they go there alive.  Revelation 20:11-15 says its wicked are brought back to life from the ground and Sheol/Hades and that the lake of fire is for them a second death (and a literal second death as taught by 2 Peter 2:6, Romans 6:23, Matthew 10:28, and so on).  Of course, there is also the chronological impossibility of the Son of Man's coming bringing about the final judgment when there is at least a thousand years between the two events.  The timing of when the sheep and the goats are judged is actually of great importance in that it would have to be consistent with all the other things taught by the Bible about eschatology, and it ultimately is.