Registered as part of God’s people is important, so much so that some Jews could not prove that they were of the priesthood. Therefore, Nehemiah had to exclude them,

These sought their listing among those who were registered by genealogy, but it was not found; therefore they were excluded from the priesthood as defiled (Nehemiah 7:64).

Likewise, we must be registered with the Lord (Psalm 87.6), that we have been born in spiritual Zion, for then we will be registered in heaven (Hebrews 12.22-24), which means that our names will be in the Lamb’s Book of Life (Revelation 20.12), otherwise, we, like the Jews in Nehemiah 7.64, will be excluded (Revelation 20.15).