“The God of the Bible does not depend on his human creatures for his well-being (see Psa. 50:8-13; Acts 17:25), nor, now that we have sinned, is He bound to show us favor.
“We can only claim from Him justice – and justice, for us, means certain condemnation. God does not owe it to anyone to stop justice from taking its course. He is not obligated to pity or pardon; if He does so it is an act, as we say, ‘of His own free will,’ and nobody forces His hand. ‘It does not depend on man’s will or effort, but on God’s mercy’ (Rom. 9:16, NEB). Grace is free, in the sense of being self-originated and of proceeding from One Who was free not to be gracious. Only when it is seen that what decides each individual’s destiny is whether or not God resolves to save him from his sins, and that this is a decision which God need not make in any single case, can one begin to grasp to biblical view of grace.”
~ J.I. Packer, Knowing God (Ch. 13, p. 132)