What is the present battle about?

Then Jesus said to those Jews who believed Him, “If you abide in My word, you are My disciples indeed. And you shall know the truth, and the truth shall make you free.”
They answered Him, “We are Abraham’s descendants, and have never been in bondage to anyone. How can You say, ‘You will be made free’?”
Jesus answered them, “Most assuredly, I say to you, whoever commits sin is a slave of sin. And a slave does not abide in the house forever, but a son abides forever. Therefore if the Son makes you free, you shall be free indeed. John 8.31-36