Excerpted from Chapter Three of Bhagavad-gita,
with the Anuvrtti Commentary of Swami B.G. Narasingha

saha-yajnah prajah srishtva purovacha prajapatih
anena prasavishyadhvam esha vo’stv ishta kamadhuk

In the beginning of creation, Brahma created mankind along with the system of sacrifice and said, “Through this sacrifice may you prosper. May it fulfill all your desires.”

devan bhavayatanena te deva bhavayantu vah
parasparam bhavayantah shreyah param avapsyatha

By pleasing the demigods, they will also please you. By mutually pleasing each other, you will attain the highest benefit.

ishtan bhogan hi vo deva dasyante yajna-bhavitah
tair dattan apradayaibhyo yo bhunkte stena eva sah

Being satisfied by your performance of sacrifices, the demigods will bestow unto you all the necessities of life. But one who enjoys these gifts without offering them to the demigods is a thief.

yajna-shishtasinah santo mucyante sarva-kilbishaih
bhunjate te tvagham papa ye pacanty-atma-karanat

Enlightened individuals are liberated from all types of karma by accepting the remnants of foodstuffs offered in sacrifice. However, those who cook for themselves perpetuate their own bondage.

annad bhavanti bhütani parjanyad anna-sambhavah
yajnad bhavati parjanyo yajnah karma-samudbhavah

All living beings subsist on food, and food is produced by rain. Rain is produced due to the performance of sacrifice, and sacrifice is born of prescribed activities.

In verse ten Brahma is mentioned as the creator. According to the Vedas, Brahma is the first living being in this universe and is manifest directly by Vishnu. Brahma’s function is as the secondary creator of the planetary systems. In modern times, some atheistic thinkers, such as Professor Richard Dawkins, an evolutionary biologist from Oxford University, have conceded that aliens from another planet may have possibly seeded life on earth. Farfetched as this may sound to some of us, the idea does come very close to the truth.
The ancient texts of India state that Brahma resides in the highest realm in the universe known as Satyaloka. Some of the offspring of Brahma known as the Prajapatis are then sent forth to seed life throughout the cosmos. But rather than look at Brahma as an alien, the Vedic texts describe him as the father of all living beings in the material world.
Since western civilization first came into contact with the pantheon of Vedic demigods there has always been the speculation that the Vedic people, often referred to as Hindus, were pagans – pagan meaning the worshipers of many gods and not one Supreme God. Thus western observers conclude that monotheism, the worship or reverence of one Supreme God, originated with the Abrahamic religions of the west. This however is not a fact.
The Vedic pantheon does indeed include many lesser demigods, but the Vedic texts are quite clear that there is only one Supreme Being or Super Consciousness that is above all. That is always referred to as Brahman, Paramatma, Bhagavan, Vishnu or Krishna. For example, the Rg Veda (1. 22. 20) states as follows:

tad vishnoh paramam padam sada pashyanti surayah
diviva cakshur atatam

The divine feet of Vishnu are like the sun above our heads, above all. His holy feet are like the vigilant eye of a grand guardian over our heads like the sun.

Srimad Bhagavatam says:

ete camsa kalah pumsah krishnas tu bhagavan svayam

The various avataras are either plenary expansions or parts of plenary expansions. But Krishna is the original source of all these avataras. (Srimad Bhagavatam 1.3.28)

Historically speaking, it is wrong to say that monotheism was developed by Abrahamic civilizations independent of any outside influence. In fact, the Abrahamic religions borrowed the idea of monotheism from the Persians after King Cyrus subjugated Babylon and Judea circa 500 BCE. Prior to the arrival of the Persians, and continuing into the 2nd and the 3rd Centuries, Judaism and Christianity were known to have belief systems based on one or more gods. Thus, monotheism only gradually developed among the Abrahamic religions.
Since the monotheistic concept found in the Vedas is much older than the Abrahamic religions, it is only logical to conclude that the later borrowed their thinking from the former. During the interim, the Persians, under the influence of Zoroaster, took the monotheistic philosophy from India and then transmitted it to the Middle Eastern civilizations. Indeed, monotheism has always been the central theme of India’s Vedic literature.
However, failing to look deeply into the philosophy of the Vedas or possibly being culturally intimidated by the superiority of Vedic knowledge as opposed to western philosophies and religions, Eurocentric academics and fundamental religionists have marginalized the ancient Vedic civilization of India. The German scholar Max Muller propagated further misinformation on this subject in the 19th century with the invention of the Aryan Invasion Theory, stating that Vedic civilization did not originate in India. Yet all this is quite far from the truth.
According to Muller, the aryans were a nomadic tribe from Europe who invaded India. Yet there is no evidence that the aryans were nomads. In fact, to suggest that a nomadic tribe of barbarians wrote literature of such profound wisdom as the Vedas defies imagination.
Furthermore, within the Vedas, there is no mention whatsoever of an original homeland, and archeologically there is a complete lack of evidence to prove an invasion ever occurred. It can only be concluded that the aryan people and Vedic knowledge were always indigenous to India.
The Vedic knowledge is that Vishnu/Krishna is Supreme and the lesser gods and goddesses such as Brahma, Shiva, Ganesha, Kartikeya, Kali and Sarasvati etc. are actually servants of the Supreme Being and are empowered with the duties of managing the universal affairs of material nature. In the above verses Sri Krishna recommends that offerings should be made to the demigods and thus the demigods will be pleased to bestow unto humanity all the necessities of life. This is, in short, a universal law of taxation. In other words, we must give the demigods their dues.
It is also intrinsic to the nature of the atma, to perform service and sacrifice. Constitutionally the atma, being part of the organic whole (the Absolute Truth), is duty bound to serve the whole, both in this life and in eternity. When sacrifice or offerings are made to Vishnu such as fruits, vegetables etc. then one’s senses become purified by eating the remnants of such offerings. But if one takes the things of this world without first acknowledging to whom they actually belong, then one simply incurs a karmic reaction. This also includes our daily food that should first be offered to Vishnu/Krishna. It will be explained by Sri Krishna later in Bhagavad-gita that these food offerings should comprise of vegetables, fruits, milk products, flowers etc. Non-vegetarian food items cannot be offered to Vishnu or Krishna – consequently the servants of Vishnu/Krishna are vegetarian. Krishna will also explain that those who serve the Absolute Truth are not duty bound to serve the demigods, nor are they bound by any other social consideration.

Read further8 Greate Philosophical Questions - A Vedic Perspective