Mistakes Have Their Purpose

…the mistakes that we have committed and the adversities that fell upon us had to be, because there was some necessity in them, some utility for our lives. But in truth these things cannot be explained mentally and should not be. For all that happened was necessary, not for any mental reason, but to lead us to something beyond what the mind imagines.
[CWM2, 3:28]

Recognise It and Don’t Repeat It

…it is not a question of being down-hearted or grieved or in despair if you have made a mistake, for every mistake can be corrected; from the moment you have found it is a mistake, there is an opportunity to work within you, to make progress and be very happy!
[CWM2, 4:116]
When one recognises one’s mistake and yet repeats it, it means that only a superficial part of the consciousness has recognised it and the rest is perfectly satisfied with it and generally justifies it. You may tell yourself without the risk of making a mistake: “If I repeat the same fault, I am not sincere.” So try to be sincere.
[CWM2, 4:15657]
Sweet Mother, one day you said that if one makes mistakes knowing that one is making a mistake, one pushes the divine Grace away and builds a wall, a veritable wall between the Divine and oneself.
…if you make a mistake knowing that it is a mistake and committing it all the same, then you do that. If through ignorance you make a mistake because you don’t know that it is a mistake, you may have very unpleasant consequences but you won’t push away the Divine, because you have done the thing through ignorance. That’s not to say that the fault is not a fault! It is a fault all the same, but as I said, you are not in the state in which you push away the divine Grace. But if you know that it is a fault and commit it all the same, each time you do so you are pushing away the divine Grace, and you push it away a little farther.
[CWM2, 6:34243]
 
Mother, there are mistakes … one knows they are mistakes, but still it is as though one were pushed into making them. Then?
Pushed by what? Ah, this is exactly what happens! It is the lower nature, the instincts of the subconscient which govern you and make you do things you should not do. And so it is a choice between your will and accepting submission. There is always a moment when one can decide. It goes to the point where as I said there is even a moment when one can decide to be ill or not to be ill. It even goes so far that a moment comes when one can decide to die or not to die. But for that one must have an extremely awakened consciousness because this speck is infinitesimal in time and like the hundredth part of a second, and because before it one can do nothing and after it one can do nothing; but at that moment one can. And if one is absolutely awake, one can, at that moment, take the decision.
[CWM2, 6:343]