The supreme dharma for all humanity is that by which one attains loving devotion to the transcendent Lord — devotion which is unmotivated and unobstructed, by which the self is fully satisfied.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स वै पुंसां परो धर्मो यतो भक्तिरधोक्षजे। अहैतुक्यप्रतिहता ययात्मा सुप्रसीदति॥
sa vai puṁsāṁ paro dharmo yato bhaktir adhokṣaje ahaituky apratihatā yayātmā suprasīdati
SB 1.2006