Far better to take refuge in God than trust in people. Psalm 118:8 (MSG)
If you were to take a good look at my soul, you'd find wounds there from people I trusted. I'm betting that we could compare scars. There are distant and hardly noticeable scars like the one I received when my friend Danny who betrayed my trust when I told him a secret in the first grade. That was long ago, but I can still see it. There are others more recent and, if you saw them, still in the process of healing.
People let me down. I let others down. Even loved ones betray trust. It's a natural part of this fallen nature we're stuck with. We choose to forgive, we let go and we press on. The wound heals over, but the mark remains if we choose to look for it. The wound continues to fester if we keep picking the scab.
I noticed that the psalmist didn't tell us not to trust people. It was just a reminder to me of where I should, ultimately, put my trust. God is a safe refuge. God may push me, challenge me, and discipline me, but he never betrays my trust.