Matthew 12:31
Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven.
Throughout the new testament, forgiveness is a prominent theme. In the old testament, while God was portrayed as angry, at times unforgiving, Jesus sought to bring a more "correct" image of God to us: that God is forgiving, and is waiting for us to come back to him. Indeed, the only sin that He does not forgive is the refusal to repent and accept His forgiveness.
Being a Christian does not stop at just learning about Christ, but also about following His footsteps.
Matthew 17:3-4
Take heed to yourselves; if your brother sins, rebuke him, and if he repents, forgive him; and if he sins against you seven times in the day, and turns to you seven times, and says, 'I repent,' you must forgive him.
We all have sinned, multiple times. And everytime we repent, God forgives. So in the same way, we must forgive others everytime they are apologetic. In fact, this is encapsulated in the "our Father" prayer that all of us recite:
And forgive us our trespasses, as we forgive those who trespass against us.
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