20 Remember that I told you, A servant is not greater than his master [is not superior to him]. If they persecuted Me, they will also persecute you; if they kept My word and obeyed My teachings, they will also keep and obey yours.
John 15:20 AMPC
Servant is not greater than the master
Persecution is a part of the Christian Faith. Jesus lets us know that we should REMEMBER that He has already warned us and told us that we will be persecuted for our faith. The reason why He warns us, is so people do not get offended and fall away. Jesus gives us a parable about the sower and the ones on stony ground fall away because of persecution.
16 And in the same way the ones sown upon stony ground are those who, when they hear the Word, at once receive and accept and welcome it with joy;
17 And they have no real root in themselves, and so they endure for a little while; then when trouble or persecution arises on account of the Word, they immediately are offended (become displeased, indignant, resentful) and they stumble and fall away.
Mark 4:16-17 AMPC
Jesus even says in John 16 about Him warning us and that we should not be offended.
I have told you all these things, so that you should not be offended (taken unawares and falter, or be caused to stumble and fall away). [I told you to keep you from being scandalized and repelled.]
John 16:1 AMPC
How do we handle persecution?
12 Be glad and supremely joyful, for your reward in heaven is great (strong and intense), for in this same way people persecuted the prophets who were before you.
Matthew 5:12 AMPC
44 But I tell you, Love your enemies and pray for those who persecute you,
Matthew 5:44 AMPC
27 But I say to you who are listening now to Me: [in order to heed, make it a practice to] love your enemies, treat well (do good to, act nobly toward) those who detest you and pursue you with hatred,
28 Invoke blessings upon and pray for the happiness of those who curse you, implore God’s blessing (favor) upon those who abuse you [who revile, reproach, disparage, and high-handedly misuse you].
Luke 6:27-28 AMPC
Jesus says that we should be glad and rejoice when we are persecuted. The apostles rejoiced when they were beaten for their faith in Acts 5:40-41.
Jesus says to pray, do well, and invoke blessings upon those who persecute us.