Certain pharases and ideas tend to be especially memorable for devotees who regularly read Srila Prabhupada’s books. One such idea is that we must know not only that God is great but also how He is great.
Here’s one example of Prabhupada making this point.
The highest summit of spiritual perfection is knowledge of the Supreme Personality of Godhead. Unless one is firmly convinced of the different opulences of the Supreme Lord, he cannot engage in devotional service. Generally people know that God is great, but they do not know in detail how God is great. Here [in Bhagavad-gita, Chapter 10] are the details. If one knows factually how God is great, then naturally he becomes a surrendered soul and engages himself in the devotional service of the Lord. When one factually knows the opulences of the Supreme, there is no alternative but to surrender to Him. This factual knowledge can be known from the descriptions in Srimad- Bhagavatam and Bhagavad-gita and similar literatures. (Bhagavad-gita 10.7, Purport)
Too many people today don’t think about God at all, and those who do have little information about Him. But the information is available. The Vedic literature teaches so much about God that even after studying it for more than forty years I’m still learning new things. Srila Prabhupada’s writings, all derived from Vedic authority, contain an abundance of material about God, and now his faithful disciples and granddisciples are producing English translations of other books, including the incomparable works of the Six Gosvamis. The Gosvamis and other prominent devotees in Lord Caitanya’s line exhaustively studied the vast Vedic literature to uncover things about God hidden from all but the most determined and qualified researcher.
The vagueness of the ill-informed conception of God hinders His appeal. Lord Caitanya and His followers presented abundant Vedic evidence to establish that Krishna is God – the original person and the source of everyone and everything. They cleared up misconceptions about other divine beings and presented encyclopedic details of Krishna’s innumerable forms. Not only can we learn about Krishna’s transcendental home, family, friends, activities, and so on, but we can also learn about these same realities in reference to His innumerable expansions and avatars. A lifetime of study is not enough to learn all there is to know about God.
The goal, of course, is not just the scholarly pursuit of information on God. Lord Krishna tells Arjuna that knowledge of Him inspires surrender to Him. “Knowledge” here implies true understanding, which can be achieved only with some faith. But anyone who truly understands how God is great will feel the stirrings of devotion.
One prominent obstacle to taking advantage of the exhaustive knowledge of God in the Vedic literature is to devalue the Vedas by labeling them a product of India, without universal relevance. The world is shrinking, however, and cultures, for better or worse, are merging. While much of value can be lost with the demise of traditional cultures, one gain may be an increased openness to “foreign” ideas. The Vedic message only seems foreign outside India. As Prabhupada would point out, gold is gold, no matter where it’s mined or minted. The treasury of Vedic wisdom is always open for withdrawals by anyone with the desire for eternal profit.