Good points Z!
Just a refresher:
And taking a cup, he offered thanks and gave it to them, saying: “Drink out of it, all of you, for this means my ‘blood of the covenant, which is to be poured out in behalf of many for forgiveness of sins. - Mt. 26: 27,28 NWT
The purpose of the WT Memorial service is to get people to reject a deal with Jesus for the "forgiveness of sins". They have been very effective in doing so.
No Apostle or Christian practiced or preached anything different from the above scripture until the WT came along with their "new light". The apostles taught that all peoples were invited to partake of the contract offered by Jesus for the forgiveness of sins in the scripture above.
Just so that everyone would know that this offer couldn't be changed until the Lords return, they wrote this stern warning:
even if we or an angel out of heaven were to declare to you as good news something beyond the good news we declared to you, let him be accursed. - Gal. 1:8 NWT
JW's need to decide which they believe more, the bible or the WT.... because on this issue they couldn't be more opposed to one another.