Answer:
The lesson learned from the story teaches that violence is very much part of the nature of man and that the fact that it is repressed does not translate to an absence of it. The extent to which each human's ability to be wicked is relative to the amount of power he can exercise at that moment.
Explanation:
First, we see a subtle kind of violence in the form of selfishness and cruelty from the rich man who though his slave served him with commitment, diligence and honesty deprived him of his wages three years in a row and would have continued had the servant not insisted on his wages.
The second of such violence is seen from the Jew who though a thief hesitated not to report another "thief" to be sentenced to death.
The other thief who thought didn't steal outrightly was worse than the first two. At the beginning of the story, he seemed like he was of a gentle heart and has a big capacity to suffer I'll wrong from others without getting offended. Alas, in the third paragraph before the last, then we see the servant now in possession of extraordinary gifts which gave him the power to make anyone dance, hit anything he aimed for, and get anything he wished for, utilizes his powers to the demise of the Jew who had tried to have him hung front.
Without careful scrutiny, it may be easily dismissed, in the case between the servant and the Jew that the Jew was at fault. However, a careful reader would observe that the servant without much thought was happy to use his powers even if it meant the death of another.
If we contrast the attitude of the servant with the rich man at the beginning of the story who withheld wages, we see that there is much difference in the level of each person's depravity, with the servant's predisposition (that has finally been revealed. A slave maltreater versus a murderer.
Cheers