Srila Prabhupada taught us that even higher than relishing our personal relationship with Lord Krishna in spontaneous devotional service is to voluntarily preach to push other living entities forward in their relationship with Lord Krishna. That voluntary spirit to please Lord Krishna, in this most confidential way, is that actual “force” which compels the conditioned souls to take up the natural process of devotional service. When we make that our genuine desire, Krishna will want nothing more than to fulfill it.
Collected Letters, vol. 2.