Forgiveness And Tawbah
If a person commits a sin and immediately repents upon realizing his mistake, God has made it incumbent upon Himself to forgive such a person. The rest of the people will be held accountable on the Day of Judgement in front of God. There God may forgive certain people or even the entire humanity due to His mercy but we should not count on that. The key thing to remember is that on the Day of Judgement no one shall be wronged.