Sometimes the unjust win. It can make you both mad and sad, but the wicked do seem to prosper and the system is set in their favor. That can be very distressing. Our friend Asaph faced that in his prayer recorded in Psalm 73.  This is just a brief excerpt: I encourage you to meditate on the complete Psalm today.

But as for me, my feet had almost slipped;
I had nearly lost my foothold.
For I envied the arrogant
when I saw the prosperity of the wicked.

They have no struggles;
their bodies are healthy and strong.
They are free from common human burdens;
they are not plagued by human ills.

I share this passage in the anger management class I teach, but the issue comes up for me sometimes too.  Yet when we have perspective on the big picture, we know that God wins in the end. So what we need to do is keep on being the hands, feet, and voice of Jesus and see how many we can bring with us to worship in his Kingdom.