Only if one can penetrate through the floor of karma or ceiling of jnana, then one can enter the room of bhakti.
Heart has 4 apartments, now fully occupied by friends and family. Bhakti means wholesale takeover of the heart, fully occupying it with Hari, Guru and Vaisnavas.
Krishna instills prema in one’s heart and then He relishes the devotees’ expression of that prema. This is pure bhakti.
Bhakti is an effort that produces bliss and work is that effort which produces exhaustion.
Prema bhakti is the real goal of chanting the holy names.
Substance of Bhakti is Surrender and Humility.