Lord Sri Krishna have specifically pointed this out in Bhagavad-Gita

yajna-dana-tapah-karma
na tyajyam karyam eva tat.
yajno danam tapas caiva
pavanani manisinam:

Act of sacrifice, charity and penance must be performed; they are not to be given up. Indeed, sacrifice, charity and penance purify even the great souls. (Bhagavad-Gita 18.5)

All the yajnas are ultimately meant to satisfy the Supreme Lord Krishna, as stated in Bhagavad-gita: "In the beginning of creation, the Lord of all creatures sent forth generations of men and demigods, along with sacrifices for Vishnu, and blessed them by saying, "Be thou happy by this yajna [sacrifice] because its performance will bestow upon you everything desirable for living happily and achieving liberation."

The highest perfection of liberated life is to associate with the Supreme Lord. Perfection is achieved by performance of yajna (sacrifice), as described above. Now, if a person is not inclined to perform yajna according to the Vedas, how can he expect a happy life even in this body, and what to speak of another body on another planet? (Purport by Srila Prabhupada on Bhagavad-Gita 3.12)

A sinful life can be counteracted by various processes of religion such as yajna, vrata and dana--that is, the performance of sacrifices, the taking of a vow for some religious ritual, and the giving of charity. In this way one may become free from the reactions of sinful life and at the same time awaken his original Krsna consciousness.

Samskaras are used for purification as well as for protection of the body and mind. During the ceremony, beneficent powers are called upon. This implies that samskaras do not only play a purely psychological role, even though this is an important aspect. They also ward off evil influences both subtle and gross. According to Gautama-dharma-sutra (8.4.26) Samskaras help to build and develop the personality on the physical, psychic, and spiritual levels. Circumstances in life that would otherwise be considered mundane become sacred, and at the same time the object is protected and secured. (Sandipani Muni)

The Sanskrit word samskara means "perfect deed". It is a purifying and sanctifying ceremony that eradicates bad karma and increases the auspicious influences of material nature. When performed in conjunction with congregational chanting of the Lord's holy names, such ceremonies offer tremendous spiritual benefit for all participants.