Peter asked Jesus how many times he should forgive, and Jesus told him seventy times seven times.

The same amount of time that God forgave Israel and gave them more time to show they were the chosen people of God.

-- Seventy weeks, seventy times seven times, 490 years, for Israel to stop sinning and anoint the Messiah --- Daniel 9:24
-- Jesus told Peter to forgive seventy times seven times --- Matthew 18:21-22

God will forgive a repentant sinner.

God uses the act of repentance as a program for changing a sinner into an obedient follower.

If a repentant sinner turns again to sin, and then again asks God for forgiveness, that repentant sinner is learning to be sincere in his act of repentance to change and cease from sin.

God will be merciful to a sinner seventy times seven times.

Luke 18:13-14 KJV
[13] And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. [14] I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.