Surrender means coming out of realm of karma
Substance of Bhakti is Surrender and Humility.
Surrender means to do anything at anytime without desire or expectation.
Patience is a symptom of surrender.
Surrendering our heart is surrendering our false ego.
Surrender sounds horrible to the one who wants to be a controller, but it is the sweetest and the most pleasing of all words for a devotee who has a humble heart.