My Spiritual Master used to send preachers who were all in the renounced order of life (sannyasis), but I am doing a completely different process - namely, preparing some young couples of husband and wife to take up this job. This is approved by Lord Caitanya. He said that it does not matter whether the preacher is in the renounced order of life, or a family man, or a brahmana or a sudra - nothing is hampering in the process of preaching Krishna Consciousness. The only qualification required is that one should know the genesis of Krishna Consciousness and then he is just the fit person to preach this great philosophy.
Letter to Isana das and Vibhavati dasi, 8 March, 1969