In Isaiah 65:4, we're told that those who eat the flesh of pigs will go to destruction. Doesn't this apply to Christians?
In Isaiah 65:4 the Lord, speaking through Isaiah, is addressing the nation of Israel. He declares that Israel has a long history of disobeying His commandments. Let's look at the passage in its proper context:
In this passage, the Lord cites numerous examples of how Israel has disobeyed the instructions given to them in the covenant of Law, including Israel's disobedience in eating pork. The people of Israel were commanded in their law to never eat pork, but the nation disobeyed the Lord nonetheless. Because of their disobedience under the Law, the Lord promises to prevent them from receiving their Messiah for a time, while the Gospel goes to the Gentiles.
The Old Covenant was only binding on Israel. It was intended to set Israel apart from the Gentile world, and it eventually gave the Lord just cause to withhold the Kingdom from Israel while offering salvation to the Gentiles. The Lord was speaking to Israel in 65:4, so His admonishment was directed to Jews alone, who were willingly violating the Old Covenant law.
Today, Christian believers in Jesus Christ are saved by the grace found in the New Covenant, and as Paul taught, we are not bound by the regulations of the Law found in the Old Covenant:
Therefore, any Gentile and all Christians are free to consume pork or anything God has made, since the regulations of the Law do not apply to those who are not bound by that covenant. Only unbelieving Israel is bound by that covenant today.
Furthermore, there is nothing inherently sinful about pork or any food. The Lord's displeasure at Israel for eating pork had nothing to do with pork itself. Just as the fruit from the Tree of the Knowledge of Good and Evil in the Garden was not inherently sinful, neither is pork inherently sinful. In both cases, the problem wasn't the food itself, for as the Paul says:
Rather, the problem in both cases was disobedience to God's word. Adam received an instruction from God, which he disobeyed resulting in God's judgment against him. Likewise, Israel received a word to abstain from pork in the covenant, yet they disobeyed, provoking His anger against them.
For more information on this issue, we invite you to read the following articles on the believer's relationship to the Law of Moses.