en_tn_condensed/jhn/11/52.md

would be gathered together into one

This is an ellipsis. The word "people" is implied by the context. Alternate translation: "would be gathered into one people" (See: rc://en/ta/man/translate/figs-ellipsis)

children of God

This refers to people who belong to God through faith in Jesus and are spiritually God's children.