I came across an interesting study about the Eucharist by a former Presbyterian pastor who apparently became Catholic. Is the Eucharist considered a "work" by some people? After reading this, I'm not sure it is a work. I have said that it is symbolic and is only done "in remembrance." This was a good read for me, a little long but worth reading.
https://chnetwork.org/2015/12/10/un...-there-is-no-life-in-you-symbolic-or-literal/
https://chnetwork.org/2015/12/10/un...-there-is-no-life-in-you-symbolic-or-literal/