Prabhupāda: Material life means when you desire to gratify your senses, that is material life. And when you desire to serve God, that is spiritual life. That is the difference between material life and spiritual life. Now we are trying to serve our senses. Instead of serving the senses, when we serve God, that is spiritual life. What is the difference between our activities and others' activities? We are using everything: table, chair, bed, this tape recorder, typewriter. So what is the difference? The difference is that we are using everything for Kṛṣṇa.
Bob: This I see. The devotees have said that the sensual pleasures that they have given up are replaced with spiritual kinds of pleasures. But see, I haven't...
Prabhupāda: Spiritual kinds of pleasure means when you desire to please Kṛṣṇa, that is spiritual pleasure. Just like example, a mother is more pleased by feeding her son. (break)
Bob: Spiritual pleasure, then, is pleasing God.
Prabhupāda: Spiritual pleasure means pleasure of Kṛṣṇa.