There are five fire sacrifices which should be made daily, if one would properly perform the Vedas.
There is the fire that burns from the combustion of fuel in a hearth. Yet the sacrifice made is by the plants - what do we give by cowering beside it? It is the holy work of gathering the fuel that makes our sacrifice - and by doing so we may discover the best fire of all: for, in this work, we will grow warmer through the right exertion of our strength.
Discovery of this second kind of fire permits the discovery of the second kind of fuel: the food we require to exert ourselves is actually a sacrifice made by numerous kinds of beings for our health and maintenance. What do we gain by their sacrifice, to be burned as energy for our work? It is the work itself that makes our sacrifice; the practice of Hatha Yoga permits our learning to take exactly what is required for the maintenance of our body - and discover what is required for the maintenance of our heart. Warming our hearts requires a third kind of fuel, and produces a third kind of fire.
The third kind of fire warms our heart by selfless service to other beings - the effort made to make the sacrifice of our food worthwhile permits us to act entirely selflessly. This Karma Yoga warms our hearts - but is not itself a sacrifice until we facilitate the growth in practice and the sacrifices of other beings as true Brahmans ought to. Karma Yoga permits the discovery of a fourth kind of fuel, a fourth fire: this one burns cold, but emits great light.
When we use our service in a way that allows others to develop the practice of Karma Yoga, we illuminate our minds. This illumination, this enlightenment, is the fourth kind of fire, fueled by Jnana Yoga. Observation of this light allows us to understand the conditions which permit fire: fuel is only one of them. A spark is required, and the fuel must be prepared. We come to understand the conditions in our own life which were prepared for our growth and success, and honor all that came before us: our parents who raised us, our ancestors who raised them, the world of beings who conditioned their success - and our own. In doing so, we kindle a fifth flame with a new kind of fuel when we discover the limitations of our perception and understanding - there are numerous beings which cannot be seen, numerous forces which defy understanding. We gain a trust in logic, and conscience - a fifth kind of fuel.
The fifth fire leads to sacrifice to the beings which we cannot see, and a logical conscience - doing what is right regardless of pain or pleasure, acting wholly in love, for love, out of love of Love, in Bhakti Yoga. Bhakti Yoga is the fifth fire; Bhakti Yoga allows us to understand the Dharma.
Understanding the Dharma we come to study it as often as possible, feeding a sixth fire - we study the Dharma a little at first, then more and more, then daily, then hourly, then constantly. We come to live the Vedas. In living the Vedas, we have performed them. And accomplished the purpose of the Fire Sacrifices.