In plain words
The Buddha did not believe in rites such as yajña and yāga. The reason is this: He held that, first of all, man must make fruitful the five senses God has granted him. Because the Buddha believed neither in the Veda nor in rites such as yajña and yāga, everyone went on calling Him an unbeliever. This is the height of Adharma. The Buddha was one whose citta was pure. He would grieve deeply on seeing the aged and those whose life is hardship. He would be much troubled to see officials and elders torment those beneath them, as a big fish swallows a small fish. He would sorrow deeply on seeing a dead body. This worldly life gave Him no satisfaction at all. He did many sādhanas to recognise the principle beyond the sun, the moon and the rest, beyond the five elements. At last, wearied, He visited many great souls and asked them to make known what the root and basis of this creation is. But not one of them could give Him a fitting answer. In the end He reached Gayā, sat there beneath a banyan tree and inquired in many ways. He recognised that Satya itself is God. He believed that true Dharma is never to hurt others by thought, word or deed. He taught, “Ahiṃsā paramo dharmaḥ.” The chief of the Buddha's teachings are Satya and Dharma. We must not break the word we have given; we must not do violence. The Veda too has taught this very thing: “Satyaṃ vada, dharmaṃ cara.”
The name first given to the Buddha was Sarvārthasiddha. On the very seventh day after He was born, His mother, Māyādevī, died. Gautamī, Śuddhodhana's second wife, brought Him up with doting fondness until He was grown. That is why He came to be called Gautama Buddha. When He was born, an astrologer came: “He must become either a great emperor. Or else He must become one wholly detached,” he said. Learning of this, Śuddhodhana sent his son nowhere. Afraid that if, when He went out, some old man or some dead body caught His eye, He might leave home in Vairāgya, he saw to it that these worldly deformities never came before His eyes; and as soon as He came of age, he gave Him in marriage Yaśodharā, the daughter of his brother-in-law, Suprabuddha. Once his son was married, he thought, there would be no chance of Him turning into one who is detached. But in the end Siddhārtha recognised the truth. “My parents, my kin, the people, all of them together married Me off and sank Me in bondage,” He grieved deeply. In His twenty-eighth year, at midnight one night, He gave up Yaśodharā, His wife, and Rāhula, His son, and, renouncing every tie, He entered the forest.
‘There is no mother, there is no father, there is no kinsman, no brother; there is no wealth, there is no house: therefore beware, beware!’
‘Birth is sorrow, old age is sorrow, a wife is sorrow, again and again; at the end of life is great sorrow: therefore beware, beware!’
This is what He taught His own heart.