What exactly is going on with the gathering of the elect in Matthew 24:31 and Mark 13:27, since the Church has already been raptured by that point? Also, does “the elect” strictly refer to the believing remnant of Israel? Even so, what is the point of this gathering, which seems to imply only believers so as to exclude this from being part of the “sheep and goats” gathering/judgment?
The term “elect” can refer to Israel, the Church, Tribulation believers, even angels. You can determine who is being referenced by the context. In Matt 24:31 notice that the elect are being gathered from one end of the Heavens to the other. Because the context of Matt. 24 is about Israel, I believe these are the spirits of dead believers from the Old Testament who will be resurrected at the time of the 2nd Coming (Daniel 12:2). The Mark passage mentions spirits in heaven as well, but tells us that there will also be believers on Earth. They’re tribulation Saints who have survived and are being called to the sheep and goat judgment. They’re the sheep who will enter the kingdom in their natural bodies to re-populate Planet Earth. The goats (surviving unbelievers) will also be gathered for judgment at the same time (Matt. 25:32).