But these things have I told you, that when the time shall come, ye may remember that I told you of them. And these things I said not unto you at the beginning, because I was with you.
Note 73 at Joh 16:4: As long as Jesus was with the disciples, He was the focus of the Jews' persecution. Any rejection the disciples encountered by association was more than compensated for by the fact that Jesus was physically present to comfort and instruct them. All this was soon to change.
After Jesus' ascension, the disciples encountered the full force of the Jews' rejection even to the point of martyrdom. Jesus assured them that His words about persecution would comfort them. He then went on to mention again the coming Holy Spirit and even stated that the comfort of the Holy Spirit would be even better because He would be in them (Joh 14:17 and 16:7).