Helaman 8

As Nephi continues to speak from his rooftop, lower judges among the crowd become angry because he exposes them and threatens their destruction both physically and spiritually. They try to stir up the crowd against Nephi and encourage them to take him to the authorities so he can be tried and convicted. They do this because they know he speaks the truth and and their fear is the people will believe him and they will lose their positions of power. But enough people in the crowd believe Nephi that the judges can't turn the crowd against him. Nephi knows he is a prophet and many of the people accept him as one. Nephi explains to the crowd that what he testifies of is no different than what all prophets have testified of. Beginning with Abraham, Nephi lists prophets down to his time including those of his own people that they have accepted in the past. The point of this, if they reject Nephi, they are rejecting all of the prophets. It's no different today. People outside the church do not see the connection between living prophets today and prophets of the past. Just as with Nephi, all prophets including ours today have testified of the same things, most importantly the atonement and resurrection of Christ. There is no other church today that correctly understands the atonement and resurrection. Just as Nephi testified to his people in his time, no other church has the priesthood keys. So what Nephi was explaining was that if they reject him, they reject all the previous prophets also. And if we reject our living prophet, we would be to doing the same. Nephi then proves his prophetic power by telling the people that their chief judge has just been murdered by his brother, both of whom were secretly joined the Gadiantons.