The surest path to happiness is to live by the principles laid down by the Lord and not disobey His established laws, which are enacted in the Vedas and the Puranasfor the forgetful living entities.
Srimad Bhagavatam 3.3.13,
Srila Prabhupada
When we keep our association with Krishna, every activity is proper and liberating, but if we disassociate ourselves from the Lord’s mercy then like a hand which is severed from the body we become ugly and useless. — In his letter to Hrisikesa, 26th Nov, 1968.
When transcendental devotional service, by which love for Krishna is attained is executed by the senses, it is called Saadhana Bhakti, or the regulative discharge of devotional service. Such devotion eternally exists within the heart of every living entity. The awakening of this eternal devotion is the potentiality of devotional service in practice. — Sri Caitanya Caritamrta, Madhya Lila, 22.105.
A pure devotee cannot forget the Supreme Lord for a moment, and similarly the Supreme Lord cannot forget His pure devotee for a moment. This is the great blessing of the Krishna conscious process of chanting the maha-mantra:
Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare,
Hare Rama, Hare Rama, Rama Rama, Hare Hare.
Bhagavad-gita 8.141,
Srila Prabhupada