According to NArada Bhakti SUtra, Bhakti represents exalted and ecstatic unconditional love towards SrI RAdhA KrshNa. It is known as prema bhakti and is eternal. On achieving the supreme stage of prema bhakti one becomes perfect, peaceful and fully satisfied. After attaining this stage, one wants nothing else, grieves not, hates not, rejoices not in materialistic pursuits.
sA tvasmin parama prema rUpA !
amruta svarUpA ca !
yal labhdvA pumAn siddho bhavatyamruto bhavati trupto bhavati !
yat prApya na kincid vAncati na Socati na dveshti na ramate notsAhI bhavati !
-- NArada Bhakti sUtra