Be careful of the word order in questions with clauses;  you don't understand what the difficulty is....  Also pay attention to formatting; a space after a comma.  I is + it (not it + is so hard to see) in a simple question.

People see what they want to see and there is so much good in the worst of us and so much bad in the best of us that it behooves none of us to judge or condemn any of us.

***********************

I can't understand

I don't understand how people are so blind with somethings,it's so hard to see the truth???I really don't understande what is the difficulty...:S