Our first international student was plugged into a mainstream Bible class designed for his grade level. It was a disaster. The kid had no idea which end was up. The teacher, who understandably, taught the class for the experience level of the majority and this left our international student in a daze.
By second semester we had a second international student and I began designing an introduction to Christianity specifically for E.L.L.s. They were so relieved. They could understand the content, ask questions without feeling stupid, and were in a "safe" environment with other non-Christian kids.
Our school has continued the class and added an introduction to world religions. The aim is to allow our international students 2 years of ELL Bible classes before we try plunking them into our mainstream classes (although one of my students asked if she could do Intro to Christianity a second time. For her it was a good choice.)