How does shakespeare develop love and tragedy?

Hi everyone, im currenly in year 11 at school and im working on an essay where i have to write how shakespeare develops love and tragedy in romeo and juliet. I have some information to write about, such as how love is compared to light, how love is described using religious words, but i dont know how he DEVELOPS these themes. i have to write about the language and dramatic devices he uses but i cant spot any of it.

If someone could help me out i would really appreciate it. Thanks