Adhering to our sadhana practices purifies our heart, and gradually allows us to develop a genuine longing to serve the Lord. When sadhana is executed with genuine longing, it has the potential to awaken bhava-bhakti. Thus if we wish to make tangible advancement, we must not allow our sadhana to become mechanical or devoid of spiritual aspiration. We must execute our daily practices with the yearning to achieve Krishna's service.
Lectures from a Disciple, Vol. 2, Sadhana-bhakti