Jesus had just been speaking of the results of our union with Him. Being connected with Him leads to the life of Christ being manifest in us, with prayerful, obedient, fruitful and loving joy being characteristic of our lives. Having said that, Jesus now tells them of some other things they can expect. He tells His disciples that they will be hated and persecuted for His name’s sake.
Jesus gives three main reasons why the world hates Christians. First, it is because we are no longer identified with the world (vs.19). Second, because we are now identified with Christ (vs.20). Third, the world rejects Christians because they are ignorant of God (vs.21).
Jesus says the world is guilty because they have rejected His words (vs.22-23), His works (vs.24), and the Old Testament witness (vs.25). But while the world has rejected the words, works, and witness of God, the disciples have not rejected God, and they will have the Holy Spirit as a witness to them and through them (vs.26-27).
Jesus tells us of these events ahead of time so that we may be prepared. To be forewarned is to be forearmed (cf. 2 Peter 3:17). This is especially true when it comes to religious leaders. While the world rejects Christians, the false religious leaders will do more than reject, they will try and suppress and even silence the voice of Christ through His disciples.
The true gospel offends people. It reminds us that we are in bondage to sin and on our way to hell apart from God’s offer of salvation in Christ. Believers are not to expect popularity in the world when we are true to His Word (2 Corinthians 2:15-16 / James 4:4). Our job is not to serve the crowd, but the Crown.