Expert: Father Dave Bechtel - 12/12/2011

Question
I have a question regarding confession.  I know you are supposed to confess all mortal sins.  What do you do when you think a sin from the past, that maybe at that time you didn't think was a sin, or thought it was only venial, but now as I have grown in knowledge I realize that certain sins were more serious than I thought when I was younger.   For example, I know that I have committed sins with the thought that I could just confess them later.  Well now I understand that is presumption.  At the time I didn't know that's what presumption was.  I feel badly about not confessing this and other sins correctly or maybe not at all.  Can I simply confess them now that I understand what they are or would all my old confessions be invalid?

Answer
Here is what you do if you want certainty regarding the issue:

Make an appointment with a priest, or simply go to Confession when it is offered at your parish.  Prior to going to Confession, examine your conscience and confess everything on your heart and mind.  If you do this, your question becomes irrelevant.

Forgetting to confess something does not invalidate a Confession.  Not confessing a sin you did not know was a sin at the time of Confession does not invalidate a Confession.  Withholding something with the intention of Confessing it later is a different matter.  To tell you the truth I am not sure if that invalidates a Confession or not.  Best case scenario you would be forgiven for everything you confessed, but not for what you intentionally withheld.  Worst case scenario the Confession would be invalid.

Thus, if you want peace of mind, simply go to Confession. That is my advice.