The best part of that article (in my opinion):
If you were invited to talk about your faith, then by all means go ahead. But if you were invited for some other reason, then offering religious testimony insults your hosts. I’ve given plenty of public speeches, many at the request of audiences who don’t share my religious views. Imagine if I told a crowded high school auditorium my joy in knowing that Jesus was not my personal savior. Christians in the audience would be deeply offended; I’d never be invited back. And rightly so.