Weakness in Krishna Consciousness we should always feel. That is a good symptom. We should never think that we are strong enough. But the source of strength is Krishna and His manifest representative, the Spiritual Master. We get this instruction from Caitanya-caritamrta that we receive the seed of Krishna Consciousness through the Spiritual Master and Krishna. Therefore, we should serve both simultaneously for continuous supply of spiritual vitality. So you are now serving Krishna under the instruction of your Spiritual Master, so there will be no scarcity of supply of strength unless there is some weakness on your part in the matter of absolute faith in these two shelters.
Letter to Jaya Govinda, 15 October, 1969