Academicians in Second Language Learning have varying responses to your question. There is no consensus, which is understandable given the variability of language learners, their objectives and the competency of their 'teachers'.
You are teaching English as a foreign language EFL and English is not your native language.
I can tell you that in China, the vast majority of native Chinese Teachers of English vary greatly in the degree of English that they use in the classroom.
I can also tell you that the general result of their efforts are college students that are relatively competent at reading, adequate at listening comprehension, and horrific at writing and speaking.
I believe that limited use of spoken English in elementary and high school classrooms in part explains these results.