'Theirs' in the Bible

"Blessed [are] the poor in spirit, because theirs is the kingdom of heaven.

Blessed [are] those who are persecuted because of righteousness, because theirs is the kingdom of heaven.

Now the group of those who believed were one heart and soul, and no one said anything of what belonged to him was his own, but all [things] were theirs in common.

having become by so much better than the angels, by as much as he has inherited a more excellent name than theirs.