Only Disciples See Christ Ascend
It is interesting to note that for some reason everyone can witness Christ descending, but only a selected special few are allowed to see Him ascend into heaven. Why do you think that is so?
3 Nephi 18:38-39
And it came to pass that when Jesus had touched them all, there came a cloud and overshadowed the multitude that they could not see Jesus.
And while they were overshadowed he departed from them, and ascended into heaven. And the disciples saw and did bear record that he ascended again into heaven.
People are fickle, and they tend to go back to old habits easily. The coming of Christ could be seen as a new start for each of them, and if he publicly ascended and made a big production of leaving them permanently in the physical sense, it would be easy for some of them to see it as a closure to that chapter of life, and thus a time to go back to the way life was before. This is certainly not the only reason that only the disciples saw the event, but I think it is one.
Interesting. I think the main reason the disciples were only the witnesses of such wonderful event is because of their faith. In John 6 starting in verse 58, Jesus is teaching in the synagogue some deep doctrine of being him the bread of life. Even the disciples were shocked by such doctrine and started murmuring. When Jesus heard that his own disciples were doubting his words he was straightforward and asked them if his words have offended them. In verse 62, he says "What and if ye shall see the Son of man ascend up where he was before?", meaning..would you still offended or doubtful EVEN if you would witness the son of God ascend to Heaven?. And many disciples left after that doctrine, except the twelve who in the last part of the chapter testified that he is the Christ, the Son of the living God. I think that proof of great faith allowed them to witness Christ's ascension.