As Christians, we are commanded to love even our enemies, but we also know that unbelievers will not return that affection. In fact, the world hates believers.
In John 15:17-18, Jesus says, "These things I command you, so that you will love one another. If the world hates you, know that it has hated me before it hated you."
As the old saying goes, oil and water don't mix.
Jesus explains further in John 17:16 why the world is hostile to His followers. "They are not of the world, just as I am not of the world."
This week, we will look at three ways we're different than the world.
First, we're different because we've been rescued from this fallen world. In verse 19, Jesus says, "If you were of the world, the world would love you as its own; but because you are not of the world, but I chose you out of the world, therefore the world hates you."
God chose us out of the world. He alone is responsible for your salvation. From the moment we're born, we're in a freefall because of sin. We can't stop ourselves. We can't fly and we have no parachute. Jesus alone must "catch us" and take us to safety.
Does it seem fair that God chooses to save some and not others? It's a question even Christians struggle with. However, if we think about it, what would be truly fair is if He condemned us all to hell.
After all, our "works of righteousness" are like filthy rags (Isaiah 64:6). If we don't have faith, everything we do is sin (Romans 14:23). Our hearts are desperately sick (Jeremiah 17:9). So sick, that we're dead in our trespasses and sin (Ephesians 2:1). That's why no one seeks after God (Romans 3:11). So, if God was going to be fair, then everyone would go to hell. But instead, because God chooses to save some, He displays that He's not only just but also merciful.
Being rescued by Jesus changes everything. We're no longer on the same trajectory as those who aren't saved. We have a new nature, but not because of anything we've done. We've been rescued, been saved, because of God's mercy. Because of this new nature, we're different.
A New Master
Second, we have a new master. From the moment we're born, we're sinners and slaves to Satan (Colossians 1:13). He is the god of this world (John 12:31; 14:30), and he has blinded the eyes of unbelievers. So, they cannot see the light of the gospel (2 Corinthians 4:4). But now we live in the Kingdom of Light.
In verse 20, Jesus implies that believers are no longer under the dominion of Satan. He is no longer our master. Instead, Christ is our master. Because Jesus is our new master, the world doesn't understand our behavior. They don't understand our way of thinking.
Unbelievers live for themselves, but believers increasingly live for the fulfillment of God's plans and purposes. We are fundamentally different than those who don't follow Jesus.
Know the Father
The third way we're different is that we know the Father.
In verse 21, Jesus says, "But all these things they will do to you for My name's sake, because they do not know the One who sent Me."
This is the heart of the problem of the world. They don't know God. Instead, they create their own gods. Just about anything can become a god. It doesn't have to be a gold, silver, or bronze idol. Children. Sports. Cellphones. Careers. Wealth. Anything we devote ourselves to.
Unbelievers don't realize they're chasing false gods. Even as Christians, we have to be careful where we devote our time and attention.
We see in John 17:3 what God wants for believers. "This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent."
So, we're different because we know the true and living God. The world doesn't. It can't without the indwelling Holy Spirit.
Contrast Between Believers and Unbelievers
When we look at verse 17 and 18, we see the contrast between Christians and the world. Believers are known for their love, and the world is known for its hatred.
Does this mean every non-Christian we meet will be cruel and mean-spirited and every believer kind and caring? We know that's not true.
But the world does not subscribe to godly values. They ignore God in their daily lives and live as they see fit. They're content to abide by their own standards, even if those standards are in blatant opposition to what God clearly lays out in His Word. As believers, our nature is to increasingly reflect the Lord's.
Have you ever noticed how someone who once pursued the pleasures of this world, someone who received encouragement from friends and family, would lose favor with these same individuals because they declared faith in Jesus Christ?
Why does this happen?
If you're feeling resistance, displeasure, hostility, rejection, and discouragement, don't take it personally. Jesus says it happened to Him first—and He's perfect. So, if Jesus is perfect and the world treated Him with hostility, don't be surprised when the world treats you the same way.
Behind the world's hatred for us is its hatred for Him. Jesus says, in John 15:23, "Whoever hates me hates my Father also."
In Matthew 12:30, Jesus says, "He who is not with Me is against Me."
There is no gray area. We either love Jesus, His Father, the Holy Spirit, and other believers, or we hate them. It doesn't matter whether someone acknowledges it or not.
D. A. Carson had an interesting take on this. He pointed out that we can see hatred for God and believers in those who claim to be tolerant of different viewpoints … except when it comes to Christian absolutes.
They demonstrate their forbearance and large-hearted goodness when they confront diverse opinions, varied lifestyles and even idiotic practices. But if some Christian claims that Christianity is exclusive (as Jesus insisted), or that moral absolutes exist because they are grounded in the character of God (as the Bible teaches) … the most intemperate language is used to (criticize them as fools). The world hates." 
You're going to face hostility from the world for being a believer. But don't take it personally. It happened to Jesus first, and He's perfect. But Jesus doesn't leave it there. He gives us the why. Why does the world treat us this way? Why is the world hostile and aggressive towards Christians? We know it happened to Jesus first. We know it's coming. We shouldn't be surprised by it. But why is it coming? Why does the world hate us? It's because we're different.
 Jesus' Farewell Discourse and Final Prayer [Baker], pp. 116-117