# and not only for the nation

The words "that he should die" are understood from the previous clause. Alternate translation: "and that he should die not only for the nation" (See: [[rc://en/ta/man/jit/figs-ellipsis]])

# 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/jit/figs-explicit]])

# children of God

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