1 Corinthians 15:6

After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep (KJV)

Then: Not only the apostles, but more than five hundred others saw Christ. Paul doesn't say, but I wonder if it happened on the day of ascension into heaven. The Corinthians probably already knew the event to which he referred. I wonder also if one or two had travelled to the Corinthian church. The Corinthians needed assurances about the future because "some are fallen asleep" before Christ has returned. That has to be a concern for those who expect to be with Christ in heaven.

Now: We are used to waiting for the Lord's return - so much so that we live our lives as if it's not going to happen for us either. We love the Lord, but we don't have that eager sense of anticipation which comes for children before Christmas or in the days before a wedding. Taking time to think about the resurrection can go a long way to restoring our longing for the Lord's early return.