"Free will" or having a unique independent personality and sense of self, means the individual jiva-souls can express themselves in their own unique way serving Krsna, voluntarily offering their own personal contributions in a "two-way" exchange.
Srila Prabhupāda - "Love means a relationship between "two persons," then there is exchange, then there is love. I must deal with you open-hearted, you must deal with me open-hearted, then there is love. So if you want to love Kṛṣṇa, God, then these thin