Passion is, in mathematical terms, "necessary but not sufficient." You also need to know how to construct a good story. You may have a genuine and deep passion for the history of table cloths, but unless you can create interesting characters and a compelling plot line, you're better off writing non-fiction about your table cloths.
Characters, too, need passion. Samuel Beckett came up in some posts. I hated Waiting for Godot. I wanted to yell at the characters, "Hey! You up there on the stage! Don't just wait -- play chess! Knit an afghan! Write a sonnet! Start a soccer league! Use your time here with some passion!" However, not everyone feels this way about Godot. I will say this, however, from 30 years of writing: It's much easier to write a good story when your characters desperately want something and act to get it.
Having "passion" for a story doesn't mean that every time you sit down at the keyboard, you're bursting with creativity (what Bruce Sterling calls "holy fire.") Sometimes you do, sometimes you don't. A useful analogy is a good marriage. Many days you actively feel love for your wife, but some days you quarrel, and some days you just wish she'd leave you alone so you can watch football in peace. Overall, however, there is genuine commitment between you two. So it is with a story for which you feel passion.