Fiction vs. Non-Fiction

As much as I enjoy writing fiction, I think my easiest writing is non-fiction. I especially like writing devotionals or Bible study materials, book reviews, memoirs and journalling.
I have so many ideas, my problem seems to be completing a project. That's the discouraging part. If I can't ever complete a story, whether fiction or non-fiction, I'll never move beyond writing for the sake of writing. I know that very few get published, and that I would still write regardless, but I have to admit that being a published author is a dream I've had since childhood. I just have to pick a project and finish it.
Of my fiction W.I.P's (works-in-progress), I feel most connected to the story set in WW2 Finland. My problem is plot, which is kind of the point of fiction, isn't it? You're supposed to have a story to tell. That setting has so much potential material and I have so many scenes already in my head. Finland's story needs to be told. I just need compelling characters and a plot for it to go somewhere. I could probably use a brainstorming session with a friend.
For non-fiction, I would like to work on my memoirs. Stop laughing. I know I'm not famous, and I haven't done much that's noteworthy, but I would like to put my memories on paper while I still remember them. Perhaps some future descendant will find them interesting. I wish I had something like that from my late father, but I digress.
The other non-fiction W.I.P. that I feel has some promise is the one I started two weeks ago, called Jesus Christ: the Scarlet Thread of the Bible. I have always loved those songs or recitations of all the books of the Bible, showing how Christ is represented in each one. But I see He's represented in more than one way in several books. I've started a devotional series looking at some of the ways Christ is hidden or hinted at in the books of the Bible. It's a huge project, and as I researched, I saw it wasn't an original thought. However, I'm not trying to do a scholarly work, although because I enjoy Theology, I would like to go in-depth. I think, though, that I'll keep it to a brief overview of each; say one or two pages, and just do a devotional style on all the types and shadows I find.
I think my unique voice comes out in my writing, even in non-fiction. I'm also finding such a blessing in the process. As much fun as writing inspirational romance is, I'm loving this series of Bible studies even more. So, a decision needs to be made. To hunker down and complete one of my writing projects this year was one of my goals. Now I have to decide whether it will be fiction or non-fiction.
Okay, I think I'm leaning to the Scarlet Thread project. Thanks for listening. You've helped me come to a decision.