You might want to combine elements from two or more themes. Put a large star on the top. On the next level more animals and figures that represent the populace. This theme is figure intensive. Ornaments representing elements of Christ's life can be placed progressively around the tree, on levels from bottom to top, or randomly.
Next Theme Decorate the tree primarily with ornaments listed in the abstract category .
You can also include figures of saints. Next Theme Decorate the tree with lots of musical instruments, angels, and ornaments listed in the abstract category . If you have little kids you could include other birthday party elements. There are many the parables about weddings and wedding feasts.