Therefore “Come out from among them and be separate, says the Lord. Do not touch what is unclean, and I will receive you.”
The apostle Paul referred to Isaiah 52:11 to help make his point that Christians are called out of the world and are to be separate—sanctified—set apart. We must live in the world, but we are not to be of the world (John 17:14-18).
William Barclay noted that this passage “is a challenge to Christians to keep themselves unspotted from the world. It has been well remarked that the very essence of the history of Israel is in the words, ‘Get thee out!’ That was the word of God that came to Abraham as the Authorized Version has it. “Get thee out of thy country and from thy kindred and from thy father’s house’ (Genesis 12:1). That was the warning that came to Lot before the destruction of Sodom and Gomorrah (Genesis 19:12-14). There are things in the world with which the Christian cannot and dare not associate himself” (William Barclay, The Daily Study Bible Series, note on 2 Corinthians 6:14 – 7:1).