The comings of Christ are often confused.  He is to come a second time to receive His own as He also will return to judge. But He first came  (in a non-physical manner) in the endtime (of the OT era) at the destruction of Jerusalem, which was also the introduction of the New Testament era.

These two comings must be understood as separate events. The first coming is mentioned in such passages as Mt.16:27, 28. Clearly, there were some listening to Jesus who would live to see that coming (as it says in v. 28).

But there are other passages to consider as well. One of these is Mt. 26:57-63. Obviously, those who would “see” the event (the coming indicated by the destruction of Jerusalem) would not live until the second coming. They “saw” that He was seated at God;s right hand by the events that occurred.

Take one more: Luke 17:20-36. The clue you need to determine which coming is in view may be found in vs. 31-32. Persons on housetops and in the fields are told not to come down or return home,  They must “get out of Dodge” immediately! Why would anyone need to be told this if he were already rising in a new body to meet Jesus in the air!

These are but samples of the two comings, which you must learn to distinguish if you would make sense of prophecy.