This is what Jesus teaches us though this answer to his disciple Peter's question. Jesus also tells a sample story (Parable) to explain how the judgment will be in the Kingdom of God. Bible Mathew 18:21-35:
Then Peter came to Jesus and asked "Lord, If my Brother keeps on sinning against me, how many times do I have to forgive him? Seven times?" "No, not seven times," answered Jesus, "but seventy times seven, because the kingdom of heaven is like this.
Once there was a king who decided to check on his servant's accounts. he had just begun to do so when one of them was brought in who owed him millions of pounds. The servant did not have enough to pay his debt, so the king ordered him to be sold as a slave, with his wife and his children and all that he had, in order to pay the debt. The servant fell on his knees before the king. 'Be patient with me,' he begged, 'and I will pay you everything!' The king felt sorry for him, so he forgave him the debt and let him go.
"Then the man went out and met one of his fellow- servants who owed him a few pounds. He grabbed him and started choking him. 'Pay back what you owe me!' he said. his fellow-servant fell down and begged him, 'Be patient with me, and I will pay you back!1 but he refused; instead he had him thrown into jail until he should pay the debt. When the other servants saw what had happened, they were very upset and went to the king and told him everything. So he called the servant in. 'you worthless slave!' he said. 'I forgave you the whole amount you owed me. just because you asked me to. You should have had mercy on your fellow-servant, just as I had mercy on you.' The king was very angry, and he sent the servant to jail to be punished until he should pay back the whole amount."
And Jesus concluded, "That this is how my Father in heaven will treat every one of you unless you forgive your brother from your heart." Mathew 18:21-35
From the above teaching of Jesus Christ on forgiveness it is clear that
1. We have to forgive one another.
2. How we forgive others will be the same way that our sins will be forgiven in the day of judgment.
3. How many times should a Christian forgive? Unlimited number of time a Christian has to forgive each other.
Read Bible for more insight and live a happy & blessed life.