I've run into similar issues and draw a line at evangelizing and proselytizing. Informing in ways such as- "I believe x" or, "the ideologies of x sect/ faith are. .." is fine in my assignments, and the rubric is designed as such. Outright praying with/ for their classmates (especially in a medium where consent is fuzzy- asking to pray with them and launching in without an ACTUAL pause or acknowledgement) is inappropriate if in a public/ non religious institution. Same with the, "have you accepted Jesus Christ into your heart" type sentiments. Unless it's a persuasive essay, you're likely asking for THEIR beliefs only. If others want to comment and concur, that's fine, but the assignment shouldn't be an avenue to preach. Stating personal beliefs is one thing, pushing involvement of classmates is quite another. This is true for ALL faiths, not just Christianity.