All activities minus God. This is material. And as soon as all activities plus God, it is spiritual. So all activities minus God means trouble, and all activities plus God is wholesome, is pleasing. So Kṛṣṇa consciousness means all activities plus God. That's all.
-Lecture -- Seattle, October 11, 1968

anarpita-carīṁ cirāt karuṇayāvatīrṇaḥ kalau
samarpayitum unnatojjvala-rasāṁ sva-bhakti-śriyam
hariḥ puraṭa-sundara-dyuti-kadamba-sandīpitaḥ
sadā hṛdaya-kandare sphuratu vaḥ śacī-nandanaḥ
May the Supreme Lord who is known as the son of Śrīmatī Śacī-devī be transcendentally situated in the innermost chambers of your heart. Resplendent with the radiance of molten gold, He has appeared in the Age of Kali by His causeless mercy to bestow what no incarnation has ever offered before: the most sublime and radiant mellow of devotional service, the mellow of conjugal love.
-CC Adi Lila 1.4