But the Jerusalem above is free, and she is our mother.
For it is written, "Rejoice, O barren one who does not bear; break forth and shout, you who are not in travail; for the children of the desolate one are many more than the children of her that is married."
Now we, brethren, like Isaac, are children of promise.
But as at that time he who was born according to the flesh persecuted him who was born according to the Spirit, so it is now.
But what does the scripture say? "Cast out the slave and her son; for the son of the slave shall not inherit with the son of the free woman."
So, brethren, we are not children of the slave but of the free woman.
Revised Standard Version of the Bible, copyright 1952 [2nd edition, 1971] by the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved. (Revised Standard Version - Holy Bible)