Śrīla Bhakti Rakṣak Śrīdhar Dev-Goswāmī Mahārāj describes spiritual purity as well as the focus one should have in practising Kṛṣṇa consciousness.
There is one striking point to be noted: purity depends on how much it is directed towards the interest of the centre. We should note this criterion with great attention. What is pure? What is the symptom of purity? As much as it is satisfactory to the central cause. Purity depends on that. All other conditions are futile. With as much earnestness as we seek that purity, our condition is so much improved. No other law is applicable. If you come to apply your legal sense there, it will be redundant.
There lies the position of the gopīs in Vṛndāvan: only Tatparatva (Brs: 1.1.12)—full attention to the centre, what will purify, or what will satisfy Him, at all risk. This is the greatness of their position there. Tatparatva: no law and no other consideration. “If a second consideration enters there, it will deviate my position.” Tatparatvena nirmalam—there is only one criterion: as much as it is satisfactory to the centre.
When Droṇāchārya educated the Kauravas and Pāṇḍavas, including Arjuna, he gave them training in archery. One day, to examine them, he put an imitation bird on the branch of a tree and asked all of his students to aim at the eye of that bird.
First he asked Yudhiṣṭhir: “We want to examine how much you have made progress in your archery learning. Try to pierce the eye of the bird there on the branch.”
“Yes.” Yudhiṣṭhir was ready.
“What do you see?”
“I see the bird.”
“And anything else?”
“Yes, the tree.”
“Anything further?”
“Yes, I see all of you.”
“Give up your bow and arrow. You won’t do it; leave it.”
Then in this way he called the others and asked them to aim at the eye of the bird.
They all said, “Yes, I see the bird.”
“Fix your aim towards the bird.”
“Yes, I am doing that.”
“What do you see?”
“I see the bird.”
“The whole of the bird?”
“Yes, the whole of the bird.”
“Anything more?”
“Yes, the branches. Yes, the top of the tree.”
“Give it up.”
Then in this way, trying a few more, he asked Arjuna.
“Arjuna, you are to pierce the eye of the bird.”
“Yes, I am ready.”
“Fix your arrow.”
“Yes.”
“What do you see?”
“I see the bird.”
“Nothing else?”
“No.”
“Neither the tree or anything else?”
“No.”
“The whole of the bird?”
“No.”
“What do you see?”
“The eye of the bird.”
“And you can see nothing else?”
“I see nothing else. I can see only the eye of the bird. I can’t see anything else.”
“Yes, you throw, throw the arrow!”
So such should be our condition, our case: only for the satisfaction of Kṛṣṇa, nothing else. His satisfaction. We shall not recognise any other thing. That is the case with the gopīs. They only see the interest of Kṛṣṇa, and nothing else, not even the whole world.