This is where you're getting Catholicism wrong. We AGREE with that.
How very subtle is your deceit!
Mrs.D, I know in your mind it's not an ongoing sacrifice. I'm sure you've convinced yourself of that.
However, Roman Catholicism's own writings, which are the official position of Roman Catholicism, say otherwise.
There is no further offering or representation of that offering per Scripture.
When we participate in the Lord's Supper as Paul described it, we "do this in remembrance of Him".
It is not to attain salvation, but a result of salvation already obtained.
Of course you do!
But then Rome goes along and ADDS different stuff for you to ALSO 'believe'.