The best response to a narc is no response! If you must respond, show no emotion... This can be very difficult, but it will deprive him of what he wants most... A narcissistic payoff from your reaction/response.
I think this really describes our spiritual walk with Jesus. If you are meant to be in a relationship with him for all eternity, it will happen. If you believe and then turn away then that is your choice. But, if you are chosen by God, called into his presence and given the gift of the Holy Spirit, then YOU ARE HIS. He will never pass you bye.