Ok, say I did not attend mass one Sunday, and it was totally my fault. Next Sunday I went to mass and recieved Holy Communion. Shortly after, I went to confession and told the priest that I had missed mass. However, at that time, I really did not even know the difference between mortal and venial sins, or that missing mass was a mortal sin, I just knew that it was bad.

I recently learned that missing Sunday mass is a mortal sin, and thus I should not have recieved Holy Communion before going to confession. Is that then a sin for having recieved the Eucharist after commiting a mortal sin even if I did not know it was a mortal sin?

If you genuinely did not know that missing Sunday mass is a mortal sin and that you should not have received Communion after having done so, then you did not commit any sin by receiving. And your last confession was valid.

Now that you know better you will, I hope, do differently in future. Might be a good idea to mention it in your next confession - not because you haven’t been forgiven, but as a way of putting a line underneath your old less-knowledgeable life. :thumbsup:

If you truly didn’t know that you shouldn’t have received communion then it probably wasn’t a mortal sin for you. However from now on you do know. You may not receive any Sacrament in a state of mortal sin except confession and baptism.You may want to confess it anyway even if it was venial. It was at least venial because as a Catholic you should be keeping yourself educated and informed about these things. You know how you knew the one thing was bad? Well, that’s good , it means your conscience is forming correctly. Keep it up!

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