These things have I spoken unto you, that ye should not be offended.
The disciples cherished the general hope of the Jewish people– that the Messiah would set up His kingdom and break the power of Rome. Instead of that, the Lord told them that He was going to die, rise again, and go back to heaven. The Holy Spirit would come, and the disciples would be sent out as witnesses for Christ. They would be hated and persecuted. The Lord told them all this in advance, so that they would not be disillusioned, made to stumble, or shocked.