Mind is seat of senses, to control mind is very important aspect. We need to understand our duty to train our mind. We need to discriminate and we need to chastise the mind sometimes, we need to distinguish what is bhakti and maya.
Even in the books of patanjali yoga, it is said that in order to attain perfection in yoga one needs Hari-bhakti. Ultimately devotion is the perfection. Narayana Smriti at the end of one's life is perfection. Normally people end their life thinking of whatever their attached to. If we are chanting the Lord's names and engage in his service then we maintain an attachment for the Lord throughout our life. The Lord will be the common denominator and pivot point in our different activities. Whatever process one is engaging in, this remembrance of Narayana, taking shelter of the Lord is the most important aspect.
Yukta Vairagya – dovetailing the material propensity for higher purpose. So that way, we get the ultimate spiritual realization and the same time we are surviving in this material world. Lord Caitanya didn't say to do 'markat-vairagya'. Markat-vairagya means monkey renunciation, looking very renounced but actually very attached. Rather, do your material duties very responsibly and attached to Krishna – that is yukta-vairagya.
Once Srila Prabhupada was teaching, how to appreciate the mercy of Lord Gaura Nitai. The mercy is so great that even the rocks melt, even the birds and the animals they crying in separation. After hearing all the philosophy and after everything is explained, of course one can theoretically understand, but still, to really understand, what is love of Krishna? One has to taste it. One can explain what is mango? its, Vitamin-C content, fat content, protein content, carbohydrate content, this vitamin, that vitamin, this fibre, this type of skin, this thickness of skin, this colour, you can get all the details but even you can say this much sugar content this everything, but still it doesn't tell you how it taste like? If you taste it, then you will get another level of understanding what it the mango. What is devotional service has been explained by Rupa Goswami here in Caitanya Caritamrita, but to really understand we need to taste it, even a drop of it and that is possible only by the mercy of Gaura-Nitai because they are so much absorbed in love of Krishna.