“And it’s hard to hate someone once you understand them.”— Lucy Christopher. Do you agree?

No, I disagree. I understand many people who I still hate. Often times, their motives are selfishness, ego, and narcissism. Doesn't mean I don't still hate them.
generally speaking, and sometimes... I somewhat agree with it
To an extent I agree. Only if the following saying applies to that person. "Monsters are not born. They are made."
Opinion
3Opinion
Unfortunately I've known a few people who are just plain selfish and inconsiderate. Sure they've had hardships, but not necessarily ones that can justify the way they treat others.
No, I'd say it's easier
To an extent, yes
Superb Opinion