In plain words
The ornaments differ; the gold is one. The colours of cattle differ; the milk is one. Living creatures differ; the jīva is one. Castes and their codes differ; birth is one. The darśanas differ; God is one. The kinds of flowers differ; the worship is one.
That is why Ātma-jñāna is the very thing that makes us see the oneness in the many. With this in view, "Īśāvāsyam idam sarvam," "Īśvara sarvabhūtānām," "Ekovasi sarvabhūtāntarātma": when we have recognised that the God who dwells in all is one, we do not put the oneness in it into practice in any way. We merely preach oneness. We utter it. But we experience separateness.
Some people keep trying to wrong God. But they think they are wronging God: this is a great mistake. No one at all can wrong God. He is wronging himself. Be it fabricated notions, deceitful notions or notions full of cunning, this is only deceiving oneself; there is no deceiving divinity at all. So whether you do good or do evil, you do it to yourself. So, recognising this truth, man must make a fitting effort to wish for the Ānanda of all beings, for the Śānti and happiness of all beings.
Yajñas, yāgas and such rites are being held for the peace of the world. What does this mean? When we have pleased God, the whole world is pleased. So these yajñas, yāgas and such rites are the very way to please God. There is another inner meaning in this too. The One who has granted everything to this world is God. To offer to Him what He has granted is the chief duty of the sādhaka. In that offering, one is only offering for one's own Ānanda; it is not that one has made any sacrifice in it.