The soldiers and the Jews knew what they were doing, they were executing a criminal as far mas they were concerned. Surely Christ was referring to the fact that they were unaware that they were committing deicide?
Of course we are not perfect, the Redemption secured for us the possibility of salvation but did not take away the flaws in our intellect and will as a result of original sin. However, God would not make it impossible for us to obey Him,  not always easy but not impossible.
I believe that if God did not love the world it would not exist.