[Avodah] basis of AZ

[Cantor Wolberg]

M.M. wrote the following:

"You want to make them righteous, but you can't show yourself and boom  
out "BE
GOOD PEOPLE", because then they'll be terrorized and have no free will."

If that's the case, then how do you explain that HaShem DID show  
Himself and boomed out "Anochi HaShem Elokecha..." etc., which  
terrorized the people but certainly
did not take away their free will?
ri