1 Cor 9 & 10 – When celebrating Easter, you are drinking from the cup of demons.

1 Cor 10:18
Look at the nation Israel; are not those who eat the sacrifices sharers in the altar?

Paul is referring to the Peace Offerings of Leviticus.

Lev 7:11-17 ‘Now this is the law of the sacrifice of peace offerings which shall be presented to the LORD. 12‘If he offers it by way of thanksgiving, then along with the sacrifice of thanksgiving he shall offer unleavened cakes mixed with oil, and unleavened wafers spread with oil, and cakes of well stirred fine flour mixed with oil. 13‘With the sacrifice of his peace offerings for thanksgiving, he shall present his offering with cakes of leavened bread. 14‘And of this he shall present one of every offering as a contribution to the LORD; it shall belong to the priest who sprinkles the blood of the peace offerings.

1 Cor 10:19
What do I mean then? That a thing sacrificed to idols is anything, or that an idol is anything?

1 Cor 10:20
No, but I say that the things which the Gentiles sacrifice, they sacrifice to demons, and not to God; and I do not want you to become sharers in demons.

Those who give sacrifices as Peace Offerings to Elohim are partakers of that altar. Likewise, those who sacrifice to demons are sharers in demons.

1 Cor 10:21
You cannot drink the cup of the Lord and the cup of demons; you cannot partake of the table of the Lord and the table of demons.

1 Cor 10:22
Or do we provoke the Lord to jealousy? We are not stronger than He, are we?

Paul says that to partake in paganism is to partake with demons. We cannot combine service to Elohim and service to demons. Indeed, Elohim does not want to be honored or served in this way.

1 Cor 10:23
All things are lawful, but not all things are profitable. All things are lawful, but not all things edify.

Paul just stated that if we participate in sacrifices to false gods, we are one with demons. Paul is still speaking of the meat of sacrifices. The meat is not evil in and of itself. The Hebrew word for "all things" is usually translated as "all." He is not saying that sin no longer exists.