Work study programs are an additional form of financial aid that is offered by the government to students who are eligible and indicate on their FAFSA that they are interested in the program. However, the jobs that a student is able to do as part of their work study are, in a way, up to the college.
Most of the time, a work study job is going to be on-campus. This can be clerical/office, computer or IT, classroom assistance, tutors, customer service, or restaurant/food workers. Part of the benefits of a work study program are that it offers an opportunity to begin getting some experience in a field you are interested in or that is related to your major.
So, if you go to a Christian college, there is more potential for a work study job that has a Christian focus or, at the very least, comes from a Christian perspective. This could be working with campus ministries or as a Teacher's Aid to a theology professor.
Some work study jobs are off campus. Typically, off campus work study jobs are focused on catering to the public interest in things like non-profit work. Sometimes it can be through a private business as well, if your school has connections with said business. Again, if you go to a Christian school, there is a higher chance that any connections the school has to get you a work study job off campus will lead to something with a Christian focus.
The specifics of what kind of jobs you can get with your work study program will depend on where you end up going to school. Talk to your financial aid office about available jobs or any connections that the college has for work study jobs.