Should he resign?
Thanks for your good mail received today.
I am also facing some problems in my Job. I am well established in my Job and work in a streamlined way to cover my work and responsibilities but my seniors think that I do nothing and am making mistakes and errors in my work. Actually, I have a heavy work load and I am covering four people’s work on my own.
Due to this, I am being disregarded in annual increments and other incentives. I have not been promoted for several years, and people who have joined the company in the last four years are getting big increments and incentives and get good ratings, even though they are not as effective as I am in their work.
I am facing several financial challenges right now, and suffering several stresses mentally and physically.
Kindly give me suitable suggestion whether I can quit this Job and search new Job or any other thing you suggest.
Kindly help me in this regards, your reply will be highly appreciated.

You always have the right to withdraw your labour and go and work elsewhere, but it is inevitably a good idea to conduct the job search while you are still in a job. I know this is difficult to do, but prospective employers always look more favourably on people in employment than those out of work.
You can always organise a quick break between your jobs if you need it, to catch up with other things in your life.
But before you do that, I think you should discuss the situation with your immediate manager. Collect your EVIDENCE of your claim that you are doing four peoples work and are being treated unfairly. You MUST have evidence to back you up. And then you must be calm and unemotional in presenting your case.
If you can successfully win your argument, then ask them to right the wrongs. Promote you as soon as possible, pay some increments, or whatever you think is reasonable. Have a list prepared. This is a negotiation.
If you can’t persuade them, or they are not prepared to right the situation, DO NOT resign on the spot. Remain dignified, and just conclude the meeting .Then job search.
Or alternatively job search first, and go to them in the knowledge that you have another job “up your sleeve”. This is your strongest negotiating position.
Good luck