Jealousy will make a person see bad, even in the good! It will bring about your destruction in many ways. Root it out of you at the earliest. If not, the next one to come is ego. Ego destroys discrimination, drives out human qualities, and turns you into a demon. Doubt, jealousy, ego and lack of faith are four very strong evil qualities. Even if any one of those four are present in anyone, without doubt, they will be ruined over time. Develop good conduct and earnestly practice good behavior as much as possible, then you will attain the status of a noble person over time. Never do any work with the desire for money or any other benefit. Expecting the result of work is greediness. The fruit of the action depends upon the action itself. Can you expect 100/100 even before you start studying? Instead of studying keeping marks in view, you must study because it is your duty, and do it with total dedication.

'My Dear Students', Vol 2, Ch 1.