tam tada manuja devam
yajanti vidyaya trayya
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In Treta-yuga, those members of human society who are fixed in religiosity and are sincerely interested in achieving the Absolute Truth worship Lord Hari, who contains within Himself all the demigods. The Lord is worshiped by the rituals of sacrifice taught in the three Vedas.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The residents of the earth in Satya-yuga are described as having all good qualities. In Treta-yuga human society is described as dharmisthah, or thoroughly religious, and brahma-vadinah, or faithfully seeking the Absolute Truth through the Vedic injunctions. However, it should be noted that all of the exalted qualities of the people of Satya-yuga are not mentioned in this verse. In other words, in Satya-yuga people are automatically perfect, whereas in Treta-yuga people are inclined to become perfect through performing Vedic sacrifice. In Treta-yuga human society is not automatically Krsna conscious, as it was in Satya-yuga, but people are still highly inclined to become Krsna conscious, and thus they strictly follow the Vedic injunctions.