God is love. A person will reap what he has sown. Those two are TRUE. How is it possible for a Father to tell his children to love one another but be hating people? The fact that it isn't right and the fact that God is right it CAN'T say what you say it says.
It is ancient words. Yes? Is it God's word? I think so. If it isn't then why are people teaching it like it is? If Psalms 11:5 are God's thoughts, then it is/was translated wrong. Is that possible in your opinion?
Look at it from God's perspective; He has an entire family of humans to get cleaned up from the mire they have been rolling in. You can relate to that if you compare it to your own family.
Say for example your goal is to help your family and that the land you lived in was ruined by man's wars and all of your watering sources were polluted from the uncleanness practiced by all of your neighbors.
You would know that these unclean sources of water breed disease and pose a very real threat of taking the life of those who you love, especially your family who are so close to you.
So you work very hard to establish a clean source of water for your family and to repair the destruction caused of war which has made you family's life very difficult.
How are you going to feel about those outsiders who disrespect what you are trying to do for your family and so they come in and undo all of your hard work, rendering it valueless to have even tried to make things better. How are you going to feel about those who haughtily do that, who refuse to listen and care any at all about what they do and how it harms your family?
This picture is presented in the scriptures.