I began service with the classic Christmas movie "The Little Drummer Boy."
For those of you who don't know the story of "The Little Drummer Boy" here's the IMDB version...
An orphan drummer boy who hated humanity finds his life changed forever when he meets three wise men on route to Bethlehem.
Long story short, he finds Jesus in the manger and his life is changed forever. It's under 25 minutes long, and fit in nicely with my lesson.
I incorporated a PowerPoint presentation with my lesson, if that's not at your tech level or in your budget then props will work fine too.