I started reading the bible because of rock opera.
Back in 1978, both my neighbor's daughter (one of the kids I babysat) and the granddaughter of one of my grandmother's friends got parts in the children's chorus of a production of Joseph and the Amazing Technicolor Dreamcoat. My grandmother thought we should go to see it, and at first I dragged my heels (an atheist, watching a religious-themed musical?). But I did go, and was completely blown away. The show was amazing, and because part of the lyrics helpfully pointed out "It's all there in Chapter thirty-nine of Genesis" I knew where to look to see what the play was supposed to be about. So I read the relevant chapters of Genesis, and saw the play twice more (I knew my mother would like the part where Pharaoh did his Elvis impression, and the last time was just because I enjoyed it).
The following year I started working backstage in the theatre, and a couple of years after that, we did Jesus Christ Superstar. Some of the songs baffled me, so again I decided to read up about the source material the play was based on.
Fast-forward a lot of years, and on to another production of Joseph; this time it was performed at Red Deer College, and as one of the front-of-house crew, I was allowed to see the play for free. This was also a very good production (someone who had seen Donny Osmond's version in Edmonton said ours was better). Where this led was me deciding to check out a series of novels by Peter Danielson - the Children of the Lion series. This series is based on the Old Testament, using biblical characters interacting with a dynasty of characters of Danielson's invention, and tying the stories to the books of Genesis, Exodus, etc. (the story of Joseph, among other strands of the overall series, runs from volume II-VII, with the main events occurring in volumes IV and V). I got curious about just how closely the novels matched the source material they were based on, so that's why I started reading the Old Testament.