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

अजोऽपि सन्नव्ययात्मा भूतानामीश्वरोऽपि सन् ।
प्रकृतिं स्वामधिष्ठाय सम्भवाम्यात्ममायया ॥ ६ ॥
Although I am unborn and My transcendental body never deteriorates, and although I am the Lord of all living entities, I still appear in every millennium in My original transcendental form.
-Bhagavad-Gita Chapter 4 Verse 6