Method 2: Explore characters who, by design or the role they play in stories, naturally have spiritual themes to them.
One great example of this is Superman.
As far as I’ve been able to determine, Superman’s creators, Jerry Siegel and Joe Shuster, didn’t plan to create a spiritually-themed character. However, they were both Jewish, so there’s probably unintentional influence there.
Many people have noted that Superman is very similar to Moses. Both of Superman and Moses’ parents send them away as babies. As adults, they both appear dramatically to many people, on missions to free the oppressed and punish the wicked.
Comparing Superman to Moses doesn’t prove Superman’s a religious character, but it shows that like Moses he plays a savior role. Many Superman stories contain savior themes and ideas (such as Superman’s title “The Man of Tomorrow,” implying he’ll lead humanity to a better future, and various stories where he helps humanity accomplish impossible goals) precisely because that’s his role in his story.
The 1978 movie Superman, co-written by Catholic screenwriter Mario Puzo, gave those savior themes a Christian tinge. Superman goes from being a Moses figure to being a Christ figure.
Like Jesus, Superman gets sent to earth by his father. Jor-El, Superman’s father comes across as a serene godlike figure. He essentially fulfills the roles of both God the Father and angel Gabriel, sending the son and heralding his destiny on earth.
Even though Jor-El dies early in the film, he speaks to his son via alien technology. So, we have a savior figure talking to his godlike father-figure in spiritual form.
When he arrives on Earth, Superman has “miraculous” powers. Granted, Superman’s powers show up immediately while we don’t know whether Jesus had miraculous abilities before he began his ministry. Still, we see a person from another place, coming to Earth with powers not of this world.
After Superman’s earthly father, Jonathon Kent, dies in Kansas, Superman leaves the Kent farm and travels into the Antarctic to build his Fortress of Solitude and figure out why he was sent to earth. No devil or temptation scene here, so it’s not an exact parallel to Jesus wandering in the wilderness.
However, the scene still involves the savior figure (Superman) going to a barren place for an initiation so he can become who he was sent to be. So, metaphorically, Superman does wander through the wilderness.
Obviously, these are heavily spiritual themes. However, they fit perfectly in the film because Superman has an inherent savior role in his story.
You don’t have to force spiritual themes into stories, sometimes you just have explore what’s already available within the story.
(Check out Part 3 here).