rewarded [shalam] me evil [ra`] for good [towb] to the spoiling [sh@kowl]
of my soul [nephesh]. KJV-Interlinear
repay me evil for good; my soul is bereft. ESV
The Lord Jesus Christ brought only good into this world and He was repaid with evil, rejection, condemnation, punishment and execution.
The spoiling of His soul refers to the ultimate rejection and abandonment of Christ.
God is truth. Humanity typically rejects truth, and not only rejects it but abandons it and replaces it with something else.
That something else is obviously not truth, and therefore lies.
Rejecting Christ means that everything used as a substitute, is a lie.
Whether it is a religious belief, a philosophical belief, a political belief, a social belief, an economic belief, or whatever, then when its basis is not found in truth, then it is a lie. And most opinions out there in this world, are formed from the foundation of lies.
To abandon the Lords soul is to abandon Him in His entirety.
There is no being half a believer, no cafeteria from which you can pick and choose between truths and lies and mix them up in your life.
You are either in compliance with truth or you are not. And when you vacillate back and forth between truth and lies then your spiritual life will be erratic at best.
However, humanity has been given everything good, and far more, and yet the vast majority of humanity remains indifferent.