For an afterschool student discussion group?
What do you think you're going to need?
A 50K seat sports arena with a rock & roll soundstage and laser light-show equipment?
Sheesh. I'm unaware of any church that doesn't have some kind of classroom sized multi-purpose room that can accommodate 20~30 people or so. Overhead or slide/movie projectors are also readily available, or can easily be donated by members of the congregation. Optionally, such items can also be readily acquired if the group has a bake sale or car wash. Religious youth groups do it all the time. If you were ever affiliated with one, you wouldn't consider such minor inconveniences to be an insurmountable obstacle.
Did you even read the article? 500 people attended this lecture.