Galatians 4:24 Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar.
25 For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children.
26 But Jerusalem which is above is free, which is the mother of us all.
27 For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath an husband.
In this passage, Paul uses historical people and places from the Old Testament to illustrate spiritual truth. Paul makes Hagar represent the Mosaic covenant which gendereth to bondage. As Hagar gave birth to Ishmael, sharing her same social status of slavery, so the law puts those subject to it in spiritual bondage.Paul viewed Hagar and Judaism in the same way, for as Hagar and her offspring were in social bondage, so Judaism and her adherents were in spiritual slavery to the law.Then we see this is speaking of the New Jerusalem where Christ reigns. Also this is speaking of the Christians, who are saved, being so many that they are impossible to number. Are you living bondage today, if so, you can be free form that if you give your life to Christ.