Humility is not a part of devotional service, it is the heart of devotional service.

The essence of spiritual life is simply to use our free will properly.

The perfection of yoga is to become detached. And the perfection of detachment is to become completely attached, attached to God.

Out of all the opulences of a living entity its humility which pleases Krishna. Other opulences can also please Krishna if offered with humility.

We can't really digest food unless there's hunger. So we can't really assimilate spiritual wisdom unless we feel the need for it.

The Absolute Truth can be perceived by a repentant heart.

Sincerity in sadhna and eagerness to serve is the basis of one's relationship with the spiritual master.