I want to approach the teaching in a positive - enjoyable way, not overly serious. Would be great if the logo shows that as well.
Would be great if the logo could have some movement implied for future use with video courses. (something within the logo that could potentially be animated on video)
Colour blue often associated with Greek and Greece.  
Font types like Gelio Greek Diner also underline the Greek identity.  It may work to try something like that

I am extremely happy with the design Ollie made for me.  He is very responsive and just a pleasure to work with.  I can recommend his services wholeheartedly

Bite Size Bible Greek