The sacrifice Jesus made for us never ends. It is beyound time and thus timeless. When Jesus died on the cross, that exact moment in time is what saved people before, saves us now and will save others in the future. Thus it is beyond time. We continue to be saved today by His sacrifice on the cross 2,000 years ago.
Consider the US Constitution. It did not end rights for us when it was written over 200 years ago did it? No, it continues to give us rights today. Thus it is a living document of sorts that has been timeless so far too. Just a similar example.
Jesus is also present with us as the Eucharist. Since Gods power to transform bread into Body works through the preist to bring the Eucharist to us in each mass, since Jesus was the sacrifice, the lamb of God, real food, He is brought present to us in mass. Thus we say “may our sacrifice be worthy of you” or something close to it. Jesus IS the sacrifice. His sacrifice is still working today to forgive our sins, it never stopped. Thus His sacrifice continues today without end.
Jesus is not resacrificed or sacriced again and again. He made ONE sacrifice for us that never ends and is timeless. Clear to Catholics - pure mud to Protestants I guess? It won’t fit with their man-made opinions on salvation?
Hope this helps, I kept it short I hope it’s clear.