What is the relationship between penitence and faith?

Sam Waldron explains in this video that Martin Luther stated that any faith that did not emerge from the womb of penitence was not true faith. Faith was not simply some historical objective. For Luther, faith was a momentous experience where one comes face to face with their sins and realizes that their sins will send them to hell.

It is a radical change of mind regarding how important and horrible sin is. It is only out of that experience of the vileness of sin that faith truly emerges. A Christian's faith is always born out of the realization that he needs Christ and His righteousness to be imputed. It cannot be trivial or lighthearted. 

Matthew 11:28-30 (NKJV) - "Come to Me, all you who labor and are heavy laden, and I will give you rest. Take My yoke upon you and learn from Me, for I am gentle and lowly in heart, and you will find rest for your souls. For My yoke is easy and My burden is light.”

Luther, penitence was the womb of faith. Any faith that did not emerge from the womb of penitence for Luther was not who faith was. That is to say, faith for Luther was not simply some historical objective assent to certain facts. For Luther, faith was this, was this, I'm trying to think of how to best describe it, was this earthquake kind of experience in which one comes face to face with their sins, feels their sins keenly, and realizes that those sins are going to send them to hell. And there is this radical change of mind about how important and horrible and its effect sin is, and it's only out of that experience, that deep experience of the vileness, of the sting of sin, that faith truly emerges.

And so for Luther to say that the Christian man is always a penitent is to say that his faith is always born out of this deep experience of his own sin and out of this deep conviction that he needs Christ and his righteousness imputed to him to be saved from his sins. But this faith can never be trivial, It can never be a lighthearted kind of thing. It can never be something that is just an objective asset. It's always this emotional thing that emerges out of the womb of penitence and conviction of sin and out of humiliation for sin and a sense of the deadliness and wickedness of sin. And so that's why Luther can say, in no way contradicting the doctrine of faith alone, in fact he's articulating it when he says that the Christian is always a sinner, always a penitent, always a righteous man.