How can we progress from sadhana bhakti to raganuga-bhakti?
Sadhana-bhakti does not exclude raganuga-bhakti. It does not require lifetimes of commitment to vaidhi-sadhana-bhakti to come to the platform of raganuga-sadhana-bhakti. It sometimes takes lifetimes of association with devotees to develop a strong commitment to sadhana-bhakti, but once we have commited ourselves, we may come to the platform of spontaneous attraction to devotional service in one lifetime. To practice raganuga-bhakti requires commitment and taste. If we want to awaken taste, we must associate with devotees who already experience it and serve them. How can we serve such devotees? We can begin by hearing from them. Our qualification for advancement in sadhana-bhakti depends on the strength of our taste or attraction to Krishna. The more pronounced our taste, the greater our qualification. If we want to develop taste, then we must show Krishna that we want it. It is not improper to want a taste for spiritual life. But our service cannot become conditional upon whether or not we receive it. The whole purpose of service is to awaken taste. Service should be rendered with yearning. If we do not yet yearn for Krishna with our whole heart, we should perform our service regretting that we do not yet have bhakti. That feeling will bring us to taste.
(LFD, Vol2, The Process for Awakening Bhakti, Pg 30 and 31