Nowhere in the New Testament is racial intermarriage ever forbidden.
A reading of the New Testament will reveal that many sins are listed for Christians to avoid, but marriages between the races is not one of them.
He also had mixed marriages forbidden when they threatened to turn Israel to other gods.
In this case, the mixture was a mixture of religion. Much of the Old Testament is a physical type of the spiritual reality revealed in the New Testament, and once the spiritual reality has come, the physical type passes away.
Christian singles are not to marry outside the faith (1 Corinthians 7); doing so would make them "unequally yoked together with unbelievers" (2 Corinthians ).