You might say that the karma (result of past actions) of previous births has to be consumed in this birth and that no amount of grace can save man from that. But I assure you, you need not suffer from karma like that. When a severe pain torments you, the Doctor gives you a morphine injection and you do not feel the pain, though it is there in the body. Grace is like the morphine, the pain is not felt, though you go through it! Grace takes away the malignity of the karma, which you have to undergo. You know that there are dated drugs, which are declared ineffective after a certain date; well, the effect of karma is rendered null, though the account is there and has to be rendered.
(From : Sai Veda, The Word of God, sayings of Bhagavan Sri Sathya Sai Baba)