(Kadamba Kanana Swami, 25 December 2013, Mayapur, India, Srimad Bhagavatam 5.9.3)
The brahma-jyotir is known to be the effulgence of Krsna but if we read a little more about the brahma-jyotir then we read that it is filled with cit-kaṇaḥ. The cit-kaṇaḥ are the endless infinitesimal souls that are in there. So the whole brahma-jyotir is actually made up of souls that are in the state of being merged in brahman. So, although it looks like one all pervading effulgence, it actually consists of endless living beings.
So, in the same way, one can look at the sankirtan movement of Lord Caitanya. Although it looks like one movement, it is actually made up of individuals and each individual has to make an endeavour towards his own purity. It is not that we have to wait, “Oh when or when, will I be a pure devotee? Oh when or when, will the light go on?” No, the light will go on when we decide to turn it on. In other words, when we decide to make the commitment, at that point we will be pure devotees.