What is the New Testament application of God separating Israel from Egypt?
The New Testament application is that God draws a line of demarcation between the believer and the world, just as He separated Israel from Egypt. Paul gives the same directions in 2 Corinthians 6, teaching that believers cannot serve two masters but must be set apart from the world.
Les explains that just as God drew an invisible line around Goshen so the insects would not cross, and put a division between Israel and Egypt, so in the New Testament Paul gives the same set of directions. In 2 Corinthians 6 Paul teaches that God puts a line of demarcation between the believer and the world. Les points back to Romans 15:4, that these Old Testament things are written for our learning. God says you cannot serve two masters; you will serve one and hate the other. All through Israel's history they were told they were different, a set-apart, covenant people, and the New Testament application is the same for believers.