I think a lot of believers are afraid that if people hate them, God will punish them somehow, because they failed to win friends and influence people. I hesitate to tell people they are living in sin because I don't want people to be angry with me. But the fact that people are sinful and need a savior is at the core of the Gospel, and if I really do care about people, I will worry more about their souls than whether or not they are mad at me.
First of all, pleasing people should not be our primary motivation in life. Oftentimes, the admiration of others becomes an idol. I know that it does for me; I can't stand thinking that anyone bears me any ill will. All too often, I am willing to sacrifice what I know to be right and true in order to appease someone. But our number one priority should be pleasing God, not others. So if someone you know is living a lifestyle of partying and drinking, and you point them to Ephesians 5:18, for example, which says "And do not get drunk with win, for that is debauchery" and they get angry at you, you must know that you have done what is pleasing to God, even though at first glance your exhortation appeared unsuccessful.
However, that doesn't mean we go around telling everyone we see committing a sin that they are going to Hell. We don't know that. We need to tell them what the Bible says about sin in order to show them their need for God, but we can't pronounce a blanket condemnation on people, because we do not know if they may yet repent. Tell them about the grace Jesus offers through His death on the cross. Tell them how precious He is to you, so much so that you are willing to risk your life, never mind the possibility that they will get irritated with you, to tell people about Him. And tell them that that Jesus can set them free from their slavery to sin. Never leave out grace.
That being said, Jesus also said in John 15:18-20 "'If the world hates you, know that it has hated me before it hated you. If you were of the world, theworld 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. Remember the word that I said to you: 'A servant is not greater than his master.' If they persecuted me, they will also persecute you. If they kept my word, they will also keep yours.'"
Remember that the world crucified Jesus. We should go about our lives expecting the same. If you are not experiencing opposition from the world, then you may not be truly living out your faith. We do not set out to be counter-cultural for the sake of being counter-cultural, but following Jesus and aligning our lives with biblical standards will automatically make us counter-cultural. Be prepared for the world to hate you.
Our ordeals here on Earth are but "light, momentary affliction" when you compare them to the "eternal weight of glory" waiting for us in Heaven (2 Corinthians 4:17) And we should, along with Paul, count all things as loss for the sake of knowing Christ (see Philippians 3:7-8).
And we should rejoice. Romans 8:16-17 says "The Spirit himself bears witness with our spirit that we are children of God, and if children, then heirs--heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him." So suffering with Christ is preparing us to be glorified with Him.
I often wish that I could be a Christian in a vaccuum. I think, if only all the conditions were perfect, if I had hours set aside every day to study the Word and pray and no one to interrupt me, then I would grow closer to God. But James 1:2-4 tells us to "Count it all joy, my brothers, when you meet trials of various kinds, for you know that the testing of your faith produces steadfastness. And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing." So part of our sanctification is undergoing trials and tribulations, because it is through them that we will be perfected, not through an easy Christian life where we never encounter any obstacles.
Rejoicing in affliction is one of the hallmarks of being a true Christian, for we know that God disciplines those whom He loves, and He puts us through trials in order to sanctify us and make us more like Christ. Living a Christian life in a vacuum, where all the conditions are always perfect, will result in a very weak faith. A strong faith is one that has been tested. And how better to prove that we love God more than man than by putting us in a situation where we have to choose between God's approval and man's approval? Your choices reveal your preferences.
We can also rejoice in trials, because we are sharing in Christ's sufferings by doing so. Allowing ourselves to be poured out as a drink offering (2 Timothy 4:6) for the sake of others, for the sake of the Gospel...that should be our desire. Lord, let us lose ourselves in You. We do not seek to be hated, but we are willing to sacrifice everything in order to follow You.
Scripture references from the ESV