Strong Dedication

He must have very strong dedication for Bhakti path and Krishna Seva. He must have strong realisation for Krishna bhajan. Why he must have strong realisation for Krishna bhajan? If Sri Guru has no realisation no feeling about about Bhakti path then how he will spread to his disciples. When Guru has such pure devotion and realisation of very beautiful Krishna Bhajan Krishna Seva then it will spread in the heart of disciples.