I used to attend a Methodist church, in which my master was a class leader; he would talk most sanctimoniously about the dear Redeemer, who was sent "to preach deliverance to the captives, and set at liberty them that are bruised" —he could pray at morning, pray at noon, and pray at night; yet he could lash up my poor cousin by his two thumbs, and inflict stripes and blows upon his bare back, till the blood streamed to the ground! all the time quoting scripture, for his authority, and appealing to that passage of the Holy Bible which says, "He that knoweth his master's will, and doeth it not, shall be beaten with many stripes!" Such was the amount of this good Methodist's piety. (41-43)

This speech is filled with little vignettes: scenes of prejudice related to Christianity. By the end of the speech, Douglass has worked his way around from prejudice in the Northern church to prejudice in the Southern church. But all forms of prejudice stem from slavery, says Douglass.

Ending on this visual demonstrates the true darkness of slavery and sets the listener up to imagine how such terrible treatment could lead to prejudice against an entire race. It's the exclamation point to his thoughts about religious hypocrisy.

Douglass doesn't come right out and say, "Wow, what an awful guy." Instead, he gives his listeners the evidence, and lets them come to that conclusion themselves.

Not hard to do.