'Children' in the Bible

So we also, when we were children, were held in bondage under the principles of the world;

my children, of whom I again travail in birth until Christ shall have been formed in you:

For Hagar is mount Sinai in Arabia, and corresponds to Jerusalem which is now, for she is in bondage with her children;

For it is written, Rejoice, thou barren that bearest not; break out and cry, thou that travailest not; because the children of the desolate are more numerous than those of her that has a husband.

But ye, brethren, after the pattern of Isaac, are children of promise.

So then, brethren, we are not maid servant's children, but children of the free woman.