I have many that have lied on me, wronged me, falsely accused me, discredited me, smeared my name and so forth, but I'm reminded that although the flesh would've like to seek vengeance and vindication - the love of God restrained me. Instead, with each hurt, I grew in mercy and forgiveness for the wrongdoer. If you do this, you will never become bitter! It won't matter what they say about you, what they do to you... you will grow in the perfect love of Christ and share in His sufferings.
I'm reminded of the great love chapter, Corinthians 13, and how it tells us that the first thing we should seek above all is what? LOVE (charity)! You can have a lot of things but if you don't have love - you're nothing God says! The first commandment is to love God and the second is to love thy neighbour as thyself. It goes on to say in Romans: Love worketh no ill to his neighbour: therefore love is the fulfilling of the law. Think about that for a while.
Even when someone does wrong to us and never says they are sorry, we are still to have mercy and forgive them. If they were true Christians, they would follow the Bible and come to you and work it out! I've always found that those who can't say they are sorry, are not real Christians, they are wolves in sheep's clothing and they will only do more harm to you and others. We should pray for them as they are truly, our enemies. They may have the spirit of narcissism, which comes along with a lot of religious leaders unfortunately, supposing that they themselves are God. They seek their own worship, they are never wrong and they will discredit anyone that threatens their worshipers from idolizing them. This one is easy - find a Godly Pastor who doesn't humiliate you to correct you, doesn't use his pulpit to slander others and does all things in the spirit of love, and you will stay far from the spirit of narcissism, but most importantly a false prophet!
But what about the friends that believe the lies? Well, it is a good time that you found out that some people will believe a lie way before they believe the truth! Or as the adage goes - A lie can travel halfway around the world while the truth is still putting on its shoes. Ain't that the truth!? You will find that true friends will find both sides of the story and pray and seek God before they react. Anyone that doesn't - count it a blessing from God that they are removed from your life! God has saved me a lot of trouble in my life by this very thing, He knows how to weed out the tares!
It isn't up to us to seek vengeance. God sees it all! Every word, every slander, every false accusation - God sees it all. It may hurt to be lied on unjustly but we will find our healing in mercy and forgiveness. We can't allow the root of bitterness to spring up in us and defile us! That is what Satan would want but we can rather, grin and bear it - stay sweet in our souls and pray that others will repent in time and come to know true Godly love. Maybe, just maybe, our correct love response will bring them to shame for their evil, we could only hope.