What could be a possible way or reason to disagree with this quote?
"Where justice is denied, where poverty is enforced, where ignorance prevails, and where any one class is made to feel that society is an organized conspiracy to oppress, rob, and degrade them, neither persons nor property will be safe,” - Frederick Douglass
One way to disagree with this is to argue that it simply is not true in all cases. There are many examples of groups of people who have had justice denied, poverty enforced, and all the rest without doing much, if anything, to endanger people or property.
In a sense, you can even say that slavery in the American South showed this. Yes, there were slave rebellions, but they were few and far between. It is not as if slaveowners' persons and property were typically unsafe because of the ways in which they oppressed their slaves. You could look at an example like the Burakumin in Japan. These are people who have been systematically discriminated against for centuries and who have not risen up in any meaningful way.
Around the world, there have been many oppressed groups who have rarely or never risen up in rebellion. That would seem to disprove this quote.