“you will see the Son of Man sitting at the right hand of Power, and coming with the clouds of heaven.” The most natural reading of this verse is that Jesus is specifically speaking to the leaders in front of him and saying that they would see him come down from heaven. This would then fit with all the other places in which Jesus indicated that his return would occur during the lifetime of the generation in which he lived. What Jesus said here in Mark 14:62 (cp. Matt 26:64) fits with what Jesus said to other people at other places in the Gospels, that they would be alive to see Jesus return to earth at his Second Coming. Jesus apparently thought he would return soon and spoke that way in a number of places in the Gospels.
[For a more complete explanation of this verse, see the parallel record and commentary on Matt. 26:64. For more on Jesus speaking about his Second Coming occurring soon, see commentary on Matt. 16:28. For more on the coming kingdom of Christ on earth, the Millennial Kingdom, see Appendix 3, “Christ’s Future Kingdom on Earth”].