What this represent in the Bible if not World War and...?

Jesus was born as the Lamb of God and will return as a Lion. He will punish the wicked and will overcome Satan. God will reward the faithful by giving us eternal life. Those who take part in the Great Supper will celebrate God's victory over evil, which is what the verses mean. You can be a part of the celebration or be separated from God for an eternity; it's your choice.