In Krishna consciousness, seems like there are so many rules, rituals, so much philosophy to study etc that for us to mature into pure souls, we have to practice sadhana bhakti. But, if we think about it, what really is the necessary qualification to approach Krishna? Is it my ability to perform my sadhana immaculately like waking up at 4.00am, doing my puja, chanting, service, studying scriptures etc or something else? The answer is - yes it is important to do our sadhana immaculately or at least aspire for it. But is that the whole story?
The answer, actually, is very simple. Srila Prabhupada writes in Nectar of Devotion that the ONLY qualification a devotee needs to progress in Krishna consciousness is greed or sincerity to know Krishna and serve Him. So this sincerity or greed to know/serve Krishna is an internal state of consciousness. We may perform our sadhana perfectly externally, but if we do it out of peer pressure or some other superfluous reason, then our sadhana will have minimal spiritual effect. However, if we perform our sadhana daily in an internal mood of "I want to know and be with Krishna and serve Him and His devotees"...if this is our internal consciousness, then that greed will take us to Krishna.
This concept of inner greed may sound simplistic because after all even in this world in order to gain anything material, we are greedy or sincere to achieve it. However there is a difference between this greediness and greediness for Krishna. The fundamental difference is that in this world we are greedy for things for our pleasure but to be greedy for Krishna and His service means to be greedy for His pleasure alone, to be greedy for His devotee's pleasure!
This shift of greed from myself to Krishna is the most difficult aspect. Easier said than done! But that is the point of sadhana or spiritual practice. We practice sadhana everyday only to internally make this shift of greed from "I consciousness" to "Krishna consciousness".