Hi all! I’m in RCIA, and in a worksheet given to us during a talk about confession, the heading says Though Shall Not Steal, and then underneath one of the questions was Do you waste time at work, school, or home?
Is everything on that list supposed to be a mortal sin, though? I don’t know about your list, but from my experience with reading other lists intended for examinations of conscience, I’ve seen a mix of things that are more clearly mortal (when the criteria apply) and things that are less clearly so.
For example, I’m pretty sure that your worksheet includes more obvious acts of theft, such as stealing items from work or becoming a burglar. Is “obvious” theft venial or mortal? Some of these acts, so I read, can be venial or mortal, depending on such things as the effect of the theft on the victim.
This Ask an Apologist answer mentions one such distinction, which I’ve seen in multiple places: stealing a piece of bread from a bakery will probably be a venial sin, but stealing the same quantity of bread from a beggar who needs it to live will be a mortal sin. (This distinction is actually why I first thought of theft as an example, not because of the heading on your worksheet.)
Another answer concerns lying, which is probably also on your list (presumably under the next commandment). It says that not all lies are mortal.
In a similar way, genuinely wasting time at work, school, or home is
probably also a mix, though don’t use me as the expert. Instead, I invite an expert to answer in this thread, or you may go to an expert with this idea in mind.
Also, what I’ll call an argument from silence is not particularly rigorous or impressive

, but if wasting time in itself were more clearly a mortal sin, I suspect that we would’ve heard more about “the mortal sin of wasting time” by now–whether in general or (as other people have already mentioned!) as an answer in this thread