Once you have direct experience of Krishna acting in your life, you will be convinced about Him. But that experience will only come when you surrender.
Our destiny is to rot in material world but Krishna comes to change our destiny therefore we have to surrender our free will.
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.