We are born into sin, so at some point will will fall short and sin. But the worst of it is that sin enslaves
John 8:34 Jesus replied, "Very truly I tell you, everyone who sins is a slave to sin.
I prefer 2 Peter 2:22 to describe what is going on describing a dog that lick back up his own vomit.
People don't want to return, but feel compelled to return to sin they disdain.
So Christ is the supernatural entity that has the power to break the chains of sin.
Jesus once gave the story of the Good Samaritan. In the story, the Samaritan finds the man dying on the side of the road, scoops him up, and takes him to someone to patch him up.
That is a more accurate perspective as to what is going on in relation to how dependent we need to be on Christ to overcome sin. If you think you can do it on your own, you will find out quickly you can't.
..so there is not total free will--yes?
Total free will? No. Total free will would be if you willed that you did not have a sin nature. Being born into this world, you don't have that choice, it has been made for you.
However, you do have the freedom to make one choice, that is, what to do about it. Our free will boils down to accepting or rejecting God.
You could argue that since God made everything, is in control of everything, knows the end result of everything, that there is no free will regarding anything. However, I would argue that since God is a God of love, the freedom to choose or reject him is key for this love to actually exist. For you see, love does not really exist between two parties if the two parties don't have the freedom to reject or accept the other. We see this in human relationships where some try to control the other. In such relationships, there is no love so long as one party tries to control and manipulate the other. And so it goes, God did not create evil, rather, evil is simply rejecting his love. Like darkness, evil does not really exist, it merely is a word, like darkness, that is used to describe a lack of light that does exist.
But God controlling every aspect of our existence is not what we see in the scripturas with Christ coming down to give his life for our sins, that is, God in the flesh. He came to serve, not control. It is God who gives us any freedoms we have, and it is man alone who tries to take them away.
So how can God give us free will if he controls all? That is the big mystery, but if God is capable of anything, he is capable of this.
Why would he do it is the big question? So if you were God and could control and manipulate everything, would it not get boring? It would be akin to playing tic tac toe with yourself all day. However, willfully surrender the smallest sliver of your power and control when it comes to human free will, no matter how small and insignificant we are in comparison to the universe, and it would consume all your attention.