There also exist, within Messianic Judaism, those who desire to become part of Israel by claiming descent from the lost northern tribes. This is difficult, if not impossible, to prove and is sometimes claimed on faith alone. There are some prophecies about the reunification of the Northern and Southern Tribes of Israel. However, some groups overemphasize this concept, attempt to make these prophecies come true today, or make theories of how it will occur in the future. In the extreme, these groups claim a superiority to the tribe of Judah. This type of attitude separates the people rather than uniting them in the Messiah.