Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lords table, and of the table of devils (I Corinthians 10:21).
The cup is often used in the Bible as a figure of speech denoting some important spiritual doctrine. For example, there is the cup of sin and wickedness. Ye make clean the outside of the cup and of the platter, Jesus told the hypocrites, but within they are full of extortion and excess (Matthew 23:25). Religious Babylon, the false church, is said to have a golden cup in her hand full of abominations and filthiness of her fornication (Revelation 17:4).
God, however, has a cup of wrath. For in the hand of the LORD there is a cup, and the wine is red; it is full of mixture; and He poureth out of the same: but the dregs thereof, all the wicked of the earth shall wring them out, and drink them (Psalm 75:8). The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of His indignation (Revelation 14:10).
Yet, in His grace, His cup of wrath became the cup of His own sufferings, as He drank the cup in substitution for those who deserved it. The cup which my Father hath given me, shall I not drink it? (John 18:11). This cup is the New Testament in my blood, which is shed for you (Luke 22:20).
Our own cup thereby becomes a glorious cup, imparting everlasting life. I will take the cup of salvation, and call upon the name of the LORD (Psalm 116:13). We can then testify, My cup runneth over. Surely goodness and mercy shall follow me all the days of my life: and I will dwell in the house of the LORD for ever (Psalm 23:5,6).
At the Lords Table, as we remember His shed blood and broken body, we should reflect on all the cup symbolizes. For as often as ye eat this bread, and drink this cup, ye do show the Lords death till He come (I Corinthians 11:26). HMM