Also is the want to go into missionary work after college too religious for this topic?
If you have a plan for the future, that is a great topic. Most students are just going through the motions of school, not really looking to a plan for the future. So, I think it is great to write about your plan.
I don't know if missionary work is too religious or not. It depends on what is important to you. If you are passionate about your religion it might be best to go to a school where such a topic will not be "too religious."
What are your intellectual interests? What special skills and knowledge do you want to acquire in college? Let the reader know your plan, because your plan is what makes you a good student. Tell about your plan and any steps you have taken to enact it.