Satsang by Swami SatyanandaYajna means to offer and offering happens at many levels. Dravya yajna relates to the offering of physical, material objects. In anna yajna there is offering of grains and food. In daan yajna there is offering of material wealth. Tapo yajna is the sadhana you perform to transform yourself, in which you offer all your negative qualities to the fire and become pure.
Yoga too is yajna, sacrifice. The principle of yoga is to sublimate the lower activities to higher aims. The Bhagavad Gita points out that sacrifice of knowledge, jnana yajna, is the highest offering. One does not rest in knowledge; one offers the knowledge to the source of knowledge, which is why Sri Krishna says, “All action culminates in the highest knowledge.” Every output of the energy of life at every level - physical, vital, mental and spiritual - is converted into offerings to the divine. In this way, yajna takes on different forms, indicating a process by which human beings can purify themselves and also ensure purity in the environment. Through yajna one can attain purity of speech, thought and action, and the ability to understand the link that exists between an individual and nature, and between nature and the cosmos.
The seed of yajna was sown when human beings heard the divine message: “Give, offer and do not accumulate.” In the course of time, yajna became part of the tantric and vedic traditions. Yajna represents the process of producing, distributing and then assimilating. On culmination of a sadhana, yajna is performed in order to share the attainments and the spiritual and material prosperity that has been gained. Yajna offered as a duty by those who expect no reward is considered to be sattwic. Yajna offered in expectation of reward or for the sake of ego is classed as rajasic. Yajna performed without faith, in which food is not distributed, mantras are not properly chanted and gifts are not given, is considered to be tamasic.
Yajnas were also used to propitiate the natural forces and luminous beings which govern the elements, as well as the cosmic energies and celestial events and expressions in life. Through mantra and yantra, yajna awakens the power contained within the natural forces and makes them beneficent and auspicious for development and growth. Some yajnas are designed to purify the atmosphere, the air, soil and water, and recharge them with energy. Some are to influence and control the elements, to create rain in desert areas, for example, and increase productivity. Others are for the fulfilment of desires, even for the purpose of progeny.

In the different scriptures, various forms of yajna have been described which can be performed by brahmins, householders or emperors to bring peace and prosperity. Kings used to perform the Ashwamedha yajna when they wanted to declare themselves emperor, by sending out a horse followed by their army. The horse would travel freely around the world. The rulers of whichever country it was passing through had to either seize the horse and challenge the authority of the king who had sent it by starting a war, or accept the horse and become subordinate to the king.
So yajnas had many different forms and were conducted in different ways. In modern language, we can say that yajnas are a process by which the prosperity and wealth of creation is circulated, whether material or spiritual There are vedic yajnas, tantric yajnas, pauranic yajnas and even darshanic (philosophical) yajnas. During the Treta yuga, King Dasharatha conducted the Putreshti yajna, whereby Agni was invoked, and he got four sons, Rama being the eldest. Draupadi, the wife of the Pandavas, and her brother Drishtadyumna were also born of yajna.
Other forms of vedic yajnas, such as Soma yajna, Jyotishtoma, Rajasooya and Vajapeya are well known. Yajnas such as Gayatri yajna, Vishnu yajna and Chandi yajna were also conducted during the Pauranic era. The Bhagavad Gita refers to darshanic yajnas, which are more philosophical in nature, where even an act of charity, austerity, japa or swadhyaya can be performed in the spirit of a yajna. In this way, the form and emphasis of yajna have differed according to the times, the aptitude of the performers and their needs. In today's situation we may even talk about a blood donation yajna, an eye camp yajna or even a refugee crisis yajna!
The yajnas conducted at Rikhia are simply for the purpose of inviting the divine and benevolent forces to the vicinity, so that they may crystallize here and shower their blessings on everyone present. In fact, the underlying factor common to all yajnas is that through this ritual the invisible forces (devatas) that are interspersed in the atmosphere consolidate and collect in the area where it is conducted. Just as the vapour in the air becomes water through a process of condensation, in the same way these divine forces that are pervading the akasha condense and crystallize at one place.
Therefore, a yajna is considered a very powerful and potent means for positively influencing the atmosphere that surrounds us. Yajna is known to ward off malefic events. The world situation being what it is today, it is indeed appropriate to conduct yajnas in these troubled times.