Psalms 109

This psalmist goes from asking for deliverance to asking God to punish his enemies to praying that God would bless him. From one extreme to the other. It just doesn't sit right with me. I don't get it. Did he actually think he was acting right by saying the things he did? "O God, whom I praise, do not remain silent..." v.1 "When he is tried, let him be found guilty and may his prayers condemn him..." v.7 "With my mouth I will greatly extol the Lord; in the great throng I will praise Him..." v.30 He goes from crying "save me! save me!" to "vengeance! vengeance!" to "oh God You're son good!" How can he do that? More importantly how can I? It's wrong to go from asking God to deliver me from something or to ask for a change of heart just so I can turn around to yell at someone and call them names. Then five minutes later I'm praising God with a sweet voice of innocence like nothing happened. No repentance, nothing. I have to be real with everything or God can't use me. Acting like that ruins the witness God gives me and causes more harm than good. "Be real with God and He will be real with you." Kent Matthews