The notion of pursuing your passion through your work is incorrect. Work is an avenue to fulfill your purpose. Your passion may or may not be what your work provides. If you pursue your purpose (or your calling) through work, then your passion will be cultivated.
Pursuing your purpose in work comes when you are doing something you are good at, feeling appreciated, and making people’s lives better. Pursuing your calling (or purpose) at work will allow you to feel a part of something greater than yourself. When work aligns with your purpose, you are driven by your heart, rather than money or someone else’s expectations.