Answer:
The school board as a government body cannot abridge or restrict the students' exercise of religion. You could argue that the other students walking past the wall are free t disregard the quotes on the wall. Or that if quotes from other sources such as atheists or other religions or philosophies are allowed, the quotes from the Bible should be treated as any other quotes from published literature.
Explanation: I hope this is a start for you. You will have to develop the essay and find support from the sources suggested. I am not an attorney, and have no insights into the cases mentioned.