Let us look at a verse from Bhagwad Geeta which talks about the various sacrifices:
daivam evāpare yajñaṁ
brahmāgnāv apare yajñaṁ
In the above verse Shri Krishna explains that there are some people who sacrifice their material possessions for the supreme lord(Shri Krishna) while there are many who sacrifice it to the demi-gods( like Indra, agni, vayu, surya).
Those who aspire for temporary material happiness make sacrifices to the demi-gods as explained above but those seeking for permanent bliss make sacrifices for the supreme god (Shri Krishna).
Further is explained in the verse as given below:
śabdādīn viṣayān anya
In this verse he tells that the person who seeks for higher transcendental life sacrifices the pleasures of material happiness. He tells that a true yogi sacrifices his hearing senses. He only hears words dedicated to Krishna consciousness. Further he also tells that we must never fall prey to sense gratifications and our senses must always remain under the control of our mind.
Lets take a look at another verse explaining about sacrifice:
This verse explains about the various kinds of sacrifices carried out by different people.
There are many charitable organisations all across the world which provide food, shelter, health care facilities, education and various kinds of monetary help to the poor and needy. Such people aim to obtain higher transcendental life by performing charity.
Some people travel to various places of pilgrimage for the attainment of higher planets in their next life.
Some take austere vows for the attainment of god.
Some indulge in the study of the vedas for attaining the almighty. Therefore these are some of the sacrifices that people perform to attain Krishna consciousness.
The idea is extended in the verse given below:
apāne juhvati prāṇaṁ
prāṇe ‘pānaṁ tathāpare
prāṇān prāṇeṣu juhvati
This verse explains that there are some people who control their breath to remain in trance. They curb the movement of the outgoing breath into the incoming and the incoming breath into the outgoing. There are even more who curtail their eating process and thus remain in trance.
The next verse is as follows:
sarve ‘py ete yajña-vido
yānti brahma sanātanam
Shri Krishna explains that the root cause of material existence is sense gratification. Therefore in order to curb this it is essential to control our senses.
He further tells that those who know the meaning of true sacrifice go to the eternal abode of the God.
Another verse explains it further:
nāyaṁ loko ‘sty ayajñasya
kuto ‘nyaḥ kuru-sattama
This verse explains that for living happily one has to avoid sense gratifications. A person cannot live happily until he curbs his sense enjoyments. If a person wants to attain a happy life he must practice Krishna consciousness.
Sacrifice are further explained in the following verse:
evaṁ bahu-vidhā yajñā
vitatā brahmaṇo mukhe
karma-jān viddhi tān sarvān
evaṁ jñātvā vimokṣyase
This verse tells us that there are various kinds of sacrifices that are approved by the vedas. There are different types of work which one can perform to attain liberation.
The above statement is confirmed by Shri Krishna himself in the verse given below:
śreyān dravya-mayād yajñāj
sarvaṁ karmākhilaṁ pārtha
This verse explains that the purpose of performing sacrifices is to gain release from the material desires. Once this is achieved, the person has complete knowledge and hence enjoys Krishna consciousness.
It explains that sacrifices done for material possessions without having the transcendental knowledge are only limited to material domains. Such activities never bestow any spiritual benefits and are confined only to material domains. Thus a man must perform sacrifices with doors of transcendental knowledge open for him, then only he will be able to enjoy Krishna consciousness.