The former idea means that He would be unable to have something that we do have – and value. Most of us value our bodies and the opportunities for enjoyment they afford us. The opportunities to look deep into the eyes of a loved one, hug a friend, smile, lend our hands to a worthy cause – we'd be missing out on a lot of satisfying interaction if we were just composed of some eternal and all-pervading white light. (Yes, we'd be missing out on a lot of suffering too, but imagine if the relishable activities could be had without the suffering.) There's a reason parents put their kids in “time out” when they misbehave: having to sit still is torturous. Our very nature is to be active; we relish and yearn for positive and productive engagement. In fact, we Vaisnavas consider the radical impersonalists' desire to annihilate their own individuality and merge into the “white light” of the Brahman effulgence to be a symptom of deep unhappiness. Unless one found one's relationships and other experiences as an individual person deeply frustrating, why would one ever want to commit “spiritual suicide” by annihilating that individuality?
And why should the master ever be poorer than the servants, or unable to have something good that they enjoy, in any category? No, no. He can never be deprived of anything worth having! On the contrary, His standard of enjoyment should be (and is) better than ours, since His enjoyment takes place on the transcendental spiritual platform and is composed of the exchange of nothing but pure love with His eternal devotees, whereas ours, as long as we remain conditioned, takes place in this temporary material world which is full of unlimited miseries, and is stained by ugly, selfish varieties of sickness like lust, anger and greed.
Impersonalists are right to understand that the contamination of mundane qualities cannot touch the Supreme Lord. However, since they fail to clearly understand the nature of the spiritual world and the full range of positive alternatives that are available there (in the shape of flawless, eternally happy spiritual forms, relationships and variety), they end up concluding that the spiritual world must be more or less just like this one with all the concrete, gross physical stuff removed. Since they have no knowledge of any place full of forms and variety other than the one we live in now, and since their experience with this world includes a lot of painful, disgusting crap, the two concepts unfortunately have become associated in their minds and hence they throw the baby out with the bathwater and decide that the spiritual realm must be a place of pure, abstract reality and formlessness. (For example, they might proclaim such truths as that “God is love”, but since “love” in this world is an abstract idea rather than a person, they might conclude that the same applies to God – not realizing that when you're on the spiritual plane, abstract and subtle concepts appear as visible and tangible persons and conscious objects.) This means that, whether they realize it or not, impersonalists' ideas of what the spiritual plane must be like are based on, and limited by, their experiences of living in this world. The funny part is that that's exactly what they accuse us personalists of!
I can totally see where they're coming from when they say that, because at first glance, it does appear as if personalists are the more childlike ones, claiming that the spiritual world is just more of the same stuff like what we see around us in this world, and they (impersonalists) are the ones who can look beyond and envision something different. But if you really get to know the Vaisnava tradition and explore it in depth, you'll see that we acknowledge the truth of the impersonalists' claims, then say “But there's more – go deeper!” We're aware of various layers and levels of truth within spiritual reality, which impersonalists cannot fathom until they become more childlike, humble and open-minded about what God might be, and what He might be capable of. We haven't invented or dreamed up these deeper spiritual truths; to propagate a work of imagination as the truth would be a despicable form of cheating. On the contrary, we take our information from trustworthy persons who have seen with their own eyes the truth of the descriptions in scriptures like the Srimad-Bhagavatam and Brahma-samhita. Humanity can't attain truly perfect knowledge in any way except through humbly receiving it from God Himself or from those pure souls who are in constant touch with Him.
Positive and definite force or presence is always more powerful than vague conceptions or negative lack thereof. The positive always wins out in the end. And the Vedic understanding of God is the most positive one ever. There is nothing vague or negative about Him. Aspects that are inconceivable to us, yes, there certainly may be – how could we expect otherwise? Our brains are pretty darn tiny within the endless entirety of Existence, and since the totality of Everything is contained within Him, He has to be a Personality in whom all kinds of opposites are resolved! But vague, illogical, or negative – no. Endless varieties of scriptures describe His personal qualities in minute detail and analyze them scientifically with examples to help us understand. The Vedic theological version holds up under deep and thorough scrutiny. And since we are His own parts and parcels, He naturally wishes for us nothing other than perfect health and happiness, so we experience His activities as greatly merciful. He'll conquer the world with His love, because our very nature is drawn to His sweetness, power, beauty, mercy and kindness, His unlimited pastimes and glorious qualities.
To be continued...