Within or manifested ….. in the absolute truth, they  are considered one and different simultaneously.

Some followers of the Vedas overly emphasize the oneness or overly emphasize the difference between God and His expansions , both His direct expansions and the jivas , the living entities.

In absolute terms, something within  or something external is of the same nature ,  one could say we are eternal because we come from the eternal .  Although we have always been , as much as Divinity has , because of His unlimited potential, some  potential is  manifested externally and some yet to be . God has no limit .

Srimati Radharani and  Lord Balarama are one and different from  Krishna as much as all the incarnations of God are  . From one lit  candle comes many lit candles can come is the Vedic example.

As the jiva has always been , and  of course, so has Radharani and Balarama, although they are direct expansions  from the  original  personality of Godhead Himself and the Jiva is not . The other incarnations of Godhead expand from Balarama and from him many other expansions from the expansions. Nevertheless ,  everything stems  from the unlimited potency of Krishna. Such varigatedness featuring expansions and other multifarious energies are ever expanding in bliss knowledge in the spiritual kingdoms of forever covering those who will not accept His position. Srila Jiva Goswami thd great Vedic scholar  describes this simultaneously one and difference as God making the impossible possible,  and who can argue with that.

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