“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 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.” (Shrila Prabhupada, Bhagavad-gita, 10.7 Purport)