John 15:20
“The servant is not greater than his lord. If they have persecuted Me, they will also persecute you.”
He showed that in this point they would be most His imitators. For while Christ was in the flesh, men had war with Him, but when He was translated, the battle came in the next place upon them. Then because owing to their fewness they were terrified at being about to encounter the attack of so great a multitude, He raises their souls by telling them that it was a special subject of joy that they were hated by them; “For so you shall share My sufferings. You should not therefore be troubled, for you are not better than I,” as I before told you, “The servant is not greater than his lord.” Then there is also a third source of consolation, that the Father also is insulted together with them.
Source: Homilies on the Gospel of John (New Advent)