If we do not repent of our sins we will continue to be workers of iniquity.
And what does the Bible say about workers of iniquity?
They will be cast into the furnace of everlasting fire (Matthew 13:41-42, Matthew 7:23, Matthew 25:41).
Therefore, it seems logical to me that in order to avoid those flames, we must repent of walking in the direction of sin.
In 1 John 3:9, we find that the one who is born of God "
cannot sin".
Now, John may in fact be using hyperbole; but if he is, he is exaggerating to make a point.
What point?
It is that when we become born again, we make a 180-degree turn away from sin, death, hell, and satan, towards righteousness, life, heaven, and God. We are now walking in a new direction, so that the following is true in our lives.
Pro 4:18, But the path of the just is as the shining light, that shineth more and more unto the perfect day.