Many people seem to confuse a call to obedience with moralism.
Moralism is a heresy which trusts in obedience or morality, at least partly, for salvation. But the regenerate Christian, when he hears God's law knows he can't lift a finger to obey of his own power, so it drives him to Christ from whence the power to obey flows. In other words obedience flows from the cross and does not contribute to it. We obey, not in order to be saved, but because we are. And when we dont the Spirit causes us to mourn over it, driving to the cross both for forgiveness and for the power to overcome sin.