'Children' in the Bible

My children -- I am again undergoing birth pains until Christ is formed in you!

These things may be treated as an allegory, for these women represent two covenants. One is from Mount Sinai bearing children for slavery; this is Hagar.

Now Hagar represents Mount Sinai in Arabia and corresponds to the present Jerusalem, for she is in slavery with her children.

For it is written: "Rejoice, O barren woman who does not bear children; break forth and shout, you who have no birth pains, because the children of the desolate woman are more numerous than those of the woman who has a husband."

But you, brothers and sisters, are children of the promise like Isaac.

Therefore, brothers and sisters, we are not children of the slave woman but of the free woman.