Breaking A Promise to God without doing everything to fulfill it

Is it a mortal sin to break a promise to God (something small) if one does not do their absolute best to prevent such a thing from happening?

What promise?

A mortal sin requires three conditions:

  1. Grave Matter
  2. Full Knowledge
  3. Free consent of the will.

If the matter was something very much opposed to the will of God, was committed in full knowledge of its gravity, and was done with the engagement of the will, and not out of compulsion, then it was a mortal sin. If you do not know if something is a mortal sin, then one condition has already not been met.

I notice that you have posted a number of “is it a sin?” threads. This could be an indication of some degree of scrupulosity. You ought to speak to a good and holy priest for advice on matters such as these, as posting them online will only further exacerbate a scrupulous conscience, particularly when there is a wide variance of opinions from those who might answer you. You are in my prayers.


Thank you, I appreciate it. I may just be a bit to scrupulous… however I do have one more question. Would breaking a promise to God constitute under grave matter?

It’s possible. Any sin can, under sufficient circumstances, be grave matter. There is no sin which is always venial regardless of knowledge and intent.

But sin also requires intent to sin. If you do what you can but fail, it is not sinful. So matter is irrelevant if intent is not present.

Of course, it never hurts to bring it up in confession. But I don’t think you need to rush off to find a priest.

Ok, thank you.

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