I've been thinking about this question, and I've decided i can't narrow it down to just one answer. There were 3 huge leaps of faith I made, and to me, they're all equally big.
The first is graduate school. I still don't know how this will work out for me. I mean, it's not like getting an MA in British and American Literature is a guarantee for a future career. Not even an academic career, because you have to have a PhD to be a full time English professor. I worry about it, because I know what I'm learning in grad school is not just literature. I'm learning to analyze text. I'm learning to teach. I'm sharpening my skills as a writer. These are good skills to have, especially if I don't want to just work in academia. So hopefully, this leap of faith is a good one.
The second is marriage. I got married when I was eighteen, just ten days after I graduated high school. Everybody was against this union. Everybody. People thought I wouldn't go to college. People thought the marriage would fall apart in the first year. People thought I was too young/stupid to know what I was doing. I met my husband when I was fifteen, so I knew him for three years when we got married. But I never really had any doubts that it was the right thing to do. He has always been just what I needed and wanted in a life partner. He supports me in every way possible. He put me through school. He does what I can so I can focus on my writing. He agreed to disrupt our entire lives and move from CA to Utah so I could go to grad school. If I need something, he makes it happen. Yeah, marriage isn't easy. But we've known each other for ten years now, and he's never, ever made me regret my decision for a second.
The third leap of faith I took was when I began selling books with Vivien. Of course, we already knew we wrote well together. We were writing for months before we started submitting our books. But this is my career, you know? I had to have implicit trust in her--in her style, in the way she works, that she won't leave me high and dry when we have contracts to fulfill. In theory, it's a huge risk. But I never really felt like it was a huge risk. Like my wedding, I had faith that it was the right thing to do. And Vivien has never, ever made me regret that decision. In fact, every day I find new reasons to be thankful that we took this leap together. On every level. I never would have met my beloved characters without her--and honestly, a life without Nathan (from Chasing Silver) and Jesse (from The Master Chronicles) is not a life I want to know. We've had more success together than we have separately. And more fulfilling than that, I've found my best friend, the other half of my brain, and somebody who just makes my life better.
So, those were my leaps of faith. Sometimes, you just got to go for it. Though I know that all in all, I am very fortunate (and maybe even blessed) person.
What's the biggest leap of faith you ever took?