This is an old post from January 2009. I was in the process of posting it when I read this story in The Toronto Star. How would you recommend Christians respond to such things in light of Psalm 35?
Psalm 35:12-13 (ESV)
They repay me evil for good;
my soul is bereft.
 But I, when they were sick—
I wore sackcloth;
I afflicted myself with fasting;
I prayed with head bowed on my chest.
David laments the fact that those who oppose him rejoice in his sufferings even after he had mourned for them during theirs. This is hard, but it is the Christian call. We are called to return evil with blessing. We are called to overcome evil with good. When we are opposed or falsely accused or misunderstood so that others hurt us the mind gets filled with thoughts of revenge and self pity and anger and hatred and a host of other emotions that contradict the call that God has given us to return evil with good.
The first verse of this Psalm helps us to know what we should do in such situations “Contend, O LORD, with those who contend with me.” Ask God to deal with it. Do not take matters into your own hands. Ask God to deal with the issue and with the people you struggle with. Allow God to do what He does best and trust Him to do it better than you would. You may not like the timing and you may think that God has forgotten. But He has not. Leave it with Him.
Note also in Psalm 35 that David holds nothing back regarding his assessment of what his enemies are doing to him. The ability to entrust vengeance into God’s hands is not a matter of denying the magnitude of the hurt we go through. Some think that for the real big issues, we are excused from not taking revenge and being bitter. We say things like “If you only knew what he did to me.” God knows and He still says – “return insult with blessing” and “Overcome evil with good.” Tell God in your prayers just how hurt you are. Tell him about the horrors of the actions of those who oppose you. Find in Him the consolation you need.
Does this mean don’t share it with anyone else? No. But it does mean that we pour out our hearts to Him and find Him to be what we really need.
Finally, be thankful. Philippians 4:6 is very helpful here. Be anxious for nothing but in everything, with thanksgiving make you requests made know to God. Don’t simply ask God for help. Ask God for help with thanksgiving. Say out loud what you are thankful for. It really will help you defeat the overpowering tendencies to revenge and bitterness, depression, hate, anger etc. Live like a Christian.