Job 33:26-28
King James Version
26 He shall pray unto God, and he will be favourable unto him: and he shall see his face with joy: for he will render unto man his righteousness.27 He looketh upon men, and if any say, I have sinned, and perverted that which was right, and it profited me not;
28 He will deliver his soul from going into the pit, and his life shall see the light.
From the time of Job, and probably before, God has responded to the sinners prayer.