Help me lead these young preacher's kids who've asked me to be their faculty sponsor?

I don't know what a "faculty sponsor" is at this college; it isn't a common term. However, there are a few things that you need to keep in mind. First of all, you talk about keeping them as friends. I think you need to be very careful about that. The line between students and faculty member must be very clear to them (and to you). This doesn't mean that you should be cold or distant, but that they need to see you as their kind, helpful faculty sponsor, not as their friend. Any time you are asked to spend time with students outside the classroom, the possibility exists for misunderstandings about the nature of your relationship with them, and you don't want to mislead them or to get into trouble yourself.

Secondly, you need to help them, within the parameters of your own belief system, to be what THEY want to be. It sounds like they have some respect for your beliefs, so this may not be too difficult, but it is probably important for you to do more listening to them than talking to them. You can then suggest prayer or meditation, or whatever your religion uses to get in touch with God, but if you start out by lecturing them, you will lose them.

Thirdly, don't forget your responsibilities to the college itself. Your department chair or Dean should know that you have been asked to take on this responsibility and should be okay with it. You don't want them to suddenly suggest that without their permission, you took on some kind of ministry job at the school that might contrast with what they themselves wanted to accomplish.