I've been working through Mark's Gospel in my own personal Bible study over the past couple of months. Mark 13 is a difficult chapter (although I think it's easier when you consider that essentially its describing something of the nature of Jesus' kingdom), but I think Ronald Kernaghan's commentary has helped me to unpick it.
Here's a fascinating thing the commentary showed me, unpacking these verses:
Mark 13:26-27: 'At that time men will see the Son of Man coming in clouds with great power and glory. And he will send his angels [or 'messengers'] and gather his elect from the four winds, from the ends of the earth to the ends of the heavens.'
Mark 14:61-62: 'Again the high priest asked him, "Are you the Christ, the Son of the Blessed One?" "I am," said Jesus. "And you [i.e. the Sanhedrin] will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven."'
Here's Kernaghan's commentary:
'Mark 14:62 extends the imagery of 13:26 so that the members of the Sanhedrin are told not only that they would see the Son of Man coming with the clouds, but also that they would see him seated at the right hand of God. The picture of Jesus' sitting at God's right hand recalls the concluding condemnation of the leaders of Jerusalem (12:35-37) in which Jesus quoted from Psalm 110:1: 'The Lord said to my Lord: "Sit at my right hand until I put your enemies under your feet."' That image of judgement and condemnation does not appear explicitly in Mark 13, but it is consistent with the central theme of this prophecy - the destruction of the temple. Indeed, since Jesus entered Jerusalem in 11:11 his condemnation of the temple has been the catalyst for every other event. The best answer then to the question of what they would see is the destruction of the temple. That event would be the corollary of the Son of Man's exaltation. The exaltation of the Son of Man to heaven would be an event that the chief priests, elders and scribes could not actually see because it would take place before the throne of God. The exaltation of the Son of Man, however, would also mean the destruction of the temple. In its destruction, they would see the vindication of the Son of Man.'I find this very helpful. It sheds real light on the nature of Jesus' kingdom. Jesus has been demonstrating throughout Mark's Gospel that his kingdom isn't what the disciples were expecting. It comes partially, as the word is proclaimed, rather than at once (see Mark 4). Now Jesus shows that, following judgement on Jerusalem, and as he takes his seat before the Ancient of Days (which doesn't refer to this second coming - see Daniel 7:13), his kingdom still does not come immediately in its fullness. The preaching of the gospel to the whole world will be accomplished, not through temple activity but through the Son of Man's own agents in the world. There is a period where his angels (or messengers) gather the elect before his return. His kingdom continues to grow today (even through the distribution of copies of Mark's Gospel in the FREE Gospel Project), before its consummation at his return.