The world will not be honest about its sin (15:22–24; 16:1–4).
Jesus again emphasized His words and His works. We have seen this stress throughout the Gospel of John (3:2; 5:36-38; 10:24-27; 14:10-11). The people had no “cover” for their sin. They had seen His works and heard His word, but they would not receive the truth. All the evidence was there. They weren’t honest enough to take it in and do something about it.

This statement is similar to what Jesus said to the Pharisees after He healed the blind man (John 9:39-41). They were forced to admit that Jesus healed the man born blind, but they refused to follow the evidence to its logical conclusion and trust Him. Jesus told them that it was they who were blind! But they confessed that they had seen a miracle and thus added to the guilt of their sin. They were not sinning in ignorance; they were sinning in the face of a flood of light. Why not? Because that light exposed their sin, they didn't want to face it honestly. Their attitude was much like that described in 2 Peter 3:5— “For this they willingly are ignorant."

How does the Holy Spirit comfort believers who are up against the world’s hatred and opposition? Primarily, through the Word of God. In the first place, the Spirit reminds us that this opposition is unmistakably declared by different writers of the Scriptures. In John 15:25, Jesus quotes Psalms 35:19 & 69:4. The Word told Him that the hatred of the world was not because of anything He had done to intentionally provoke such opposition. Today we can turn to passages such as Philippians 1:28–30; 2 Timothy 2:9–12; Hebrews 12:3–4; and 1 Peter 4:12ff. We also have the encouraging words of our Lord in the Gospels.

The Spirit also testifies to us and through us in times of persecution (John 15:26–27). He reminds us that what we are going through is “the fellowship of his [Christ’s] sufferings” (Philippians 3:10) and that it is a privilege to be reproached for His name. (see 1 Peter 4:12-19.)

Persecution has always been a time of proclamation and testimony for the church. When unsaved people attack us, we are to be “ready always to give an answer” (1 Peter 3:15). The Spirit testifies to us, so we can testify to the world (Mark 13:11). We cannot bear a clear testimony for Christ, except through the power of the Spirit of God (Acts 1:8).

The world heats the furnace of persecution, but there is no cause for the believer to stumble (“be offended,” John 16:1). He should expect persecution, if for no other reason than that his Lord told him it was coming. (See especially Jn. 13:19 and 14:29, where the Lord forewarned His disciples.) If this persecution is by religious people who think they are serving God, then they must not stumble. In John 16:2, the word translated “service” is referring to priestly service. This passage is certainly a description of Saul of Tarsus, who thought he was serving God by destroying the church (see Acts 7:57–8:3; 22:3–4; 26:9–12).

It is tragic when “religious” people kill and persecute in the name of God. It is true that "the blood of the martyrs is the seed of the church" (Tertullian), but their blood is also a stain on history's pages.

We are united with Christ (15:18,20).
​If they hated Him, they will hate those of us who are connected with Him. Jesus quoted this in John 15:20, the point He had made earlier, and the logic of this is clear. He is Master, we are Servants. He's bigger than us, so He has to receive the praise and glory. But the world shall not give Him praise and glory! The world hates Him, and therefore the world must hate us. If Jesus, with all His greatness and perfection, cannot escape persecution, what hope is there for us with our imperfections?

In some of the other images of the relationship between Christ and His own, this principle is evident. He is the Shepherd, and we are the sheep, and when they attack the Shepherd, it hurts the sheep (Matt. 26:31). We are the disciples, the learners, and He is the Master. But it is encouraging to know that when God’s people are persecuted, our Lord shares in their suffering, for He is the Head of the body and we are the members. “Why persecutest thou Me, Saul, Saul?” (Acts 9:4). All that the enemy can do to us has already been done to Jesus Christ, and He is “with us” in our suffering.