Chapter 9, Verse 27
"Whatever you do, Arjuna,
Whatever you say or eat,
Or pray, enjoy, or suffer,
Do them all as offerings to Me."
Doing things for others without expecting anything back is the essence of worship. That's Karma Yoga. Sometimes people ask me...
When I go to work and get my own salary, how can I call that Karma Yoga?
With your salary, you have the means to eat, to clothe yourself, and to have a roof to sleep under. If you're living to serve others, then you need to eat. You have to fill up the tank so that the car will go. You have to keep the engine lubed. With the money from your salary, you equip yourself with enough energy to give the energy back to others.
Then your eating and sleeping become Karma Yoga, because you do them with the intention of keeping yourself fit to serve others. Live to serve Krishna, or your chosen form of God, who lives in the hearts of all. Then your whole life becomes Karma Yoga. If you live for the sake of everybody, serving God and creation every minute with every breath, your worship is constant. Your life has become worship, and every act is an expression of that worship.
Here Krishna offers the sweetest solace and highest hope to all of his children, even the errant and the bewildered. Through steadfast Yoga meditation, the loving dedication of all actions to God, and rightful resolve, not only may the righteous attain Liberation, but also the most deluded may speedily emerge into sanctity, from ignorance into the healing light of wisdom.
My guru, Srila Prabhupada, used to talk about engaging the senses in Krishna's service, or using the senses for spiritual engagement, such as seeing the guru, the chelas (fellow aspirants), and the murtis (statues) in the temple, hearing kirtan (devotional chanting), japa (mantra repetition), and words of wisdom, smelling incense offered in love, touching and tasting prasad (blessed food), and so forth. He said that we can't artificially stop the senses, but we can use them for service, working for God. Then they become spiritual senses, so that all day long we are "rightly situated."