what is the lie atticus talk about? what is the reality that he is hoping the jury will see?

Atticus points out that the case comes down to the word of a black man against the word of the white people, and that the Ewells' case depends upon the jury's assumption that "all black men lie." Uncharacteristically, Atticus loosens his tie and removes his jacket, which Scout and Jem are astounded to see, because he never walks about so casually. In his final remarks, Atticus speaks directly to the jury, earnestly reminding them that there are honest and dishonest black people just as there are honest and dishonest white people. He tells the jury that in a court of law, "all men are created equal." A court is, however, no better than the members of its jury, and he urges the jury to do their duty. he hopes the jury will see reason without prejudice.