No partisan on either side of this argument wants to admit it,but the truth is the left HATES Christianity because Christianity is their PRIME competition for influence/power,and "gaining the hearts and minds" of the people,and Christianity does a MUCH better job of helping people than communism has ever done or will ever do,because Christianity doesn't try to enslave people and take away their free will.
Christianity: "God will make you free!"
Communism: "Becoming slaves to the state will make you free because you will no longer be forced to make any of your own decisions,so you won't be responsible for any mistakes.
You will be a free as a cow in the field because we will make all your decisions for you !"
Not hard to see why Communists have a chip on their shoulders,is it?
I have always believed that Marx used Christianity as the "launching pad" to "Kick-off Communism". He took what he thought would be useful,and used that as the base because it had been proven to work.
He and the communists that followed him see Communism as "Heaven on Earth,and you don't have to wait to die to enjoy it."