This is an interesting thread. God made us in His image, so we would be intelligent, understand language and be creative. But it was this desire to be more like God which brought about the fall of the human race to have a sinful nature. ". . . For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil. . . ." -- Genesis 3:5. ". . . And the LORD God said, Behold, the man is become as one of us, to know good and evil: . . ." -- Genesis 3:22.
Now it is the affect of that knowledge of evil on the human mind which causes our sinful nature. And so our being self willed is not free to be sinless. God made us good and to be self willed beings. But not being infinitely good as God is, the knowledge of evil causes thoughs which lead to sin, and by that knowledge of good we are self condemned (1 John 3:20; Matthew 12:34-36).
". . .Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness? . . ." -- Romans 6:16.
We do not have a free will were we do not sin (1 John 1:8-10 - 1 John 2:1).