How to keep yourself motivated, while you are getting paid less as compared to your experience, qualification and market trend?

First of all I like to do according to my passion , for myself salary is not main issues . I can sacrifice this issue for passion. If I have to compare with my close one then I will say maybe I have a major lacking  in my work which I could not discover for this reason I get less. Then politely I will talk to my higher one for my problem and try to negotiation .for this situation obviously I have to understand the company's current profit.