You are applying for an engineering course. Not the job of a lecturer or running a charity. Why would you mention it at all?
If any of them know about dubs they will say "let's not bother with him - witnesses always put their cult first before studies or college based activities. They dont want to contribute to the life and community of non witness students. In the bin!"
Saying you gave up da troof and no longer believe it labels you as a sucker for lost causes and a quitter. In the bin.
If you get an interview, they will notice your poise and demeanour and speaking ability anyway. If you are accepted, your other good qualities will also get noticed.