Your calling is what you are called to do by God. It is your workplace and your ministry. Our Identity gives us characteristics that help us be better at our calling than another job. Passion is related because you have to be willing to do your job and if you like doing your calling then it makes your calling easy to do. I feel like my calling is to go become an engineer. I want to show Christ to engineers or scientists who are usually atheists. In order to get there I have started to study the bible more and more ever since last year. Therefore by the time I am an engineer, I would be grounded into the rock of God so I can spread the word of God.