It's much the same as quoting Indiana Jones or Han Solo in a movie. If what's said is quotable, then I'll use it. Many people believe in the person of Jesus, and as such, I'll relate to them from that perspective. The Jesus person doesn't have to actually exist to do this. As long as the principle gets across.
Teachers come and go, but the principles always remain.
Anyhow, a teacher can only remind a person of what they've forgotten. And they're not infallible either. There are a lot of people who read the site believe in the literal person of Jesus, and that's fine. Some don't, and that's fine too. Like I've always said, the teaching of love, peace, and humanity is the important thing.