Galatians 4:26

26.But Jerusalem, which is above. The Jerusalem which he calls above, or heavenly, is not contained in heaven; nor are we to seek for it out of this world; for the Church is spread over the whole world, and is a “stranger and pilgrim on the earth.” (Hebrews 11:13.) Why then is it said to be from heaven? Because it originates in heavenly grace; for the sons of God are

“born, not of blood, nor of the will of the flesh,
nor of the will of man,” (John 1:13,)

but by the power of the Holy Spirit. The heavenly Jerusalem, which derives its origin from heaven, and dwells above by faith, is the mother of believers. To the Church, under God, we owe it that we are

“born again, not of corruptible seed, but of incorruptible,”
(1 Peter 1:23,)

and from her we obtain the milk and the food by which we are afterwards nourished.

Such are the reasons why the Church is called the mother of believers. And certainly he who refuses to be a son of the Church in vain desires to have God as his Father; for it is only through the instrumentality of the Church that we are “born of God,” (1 John 3:9,) and brought up through the various stages of childhood and youth, till we arrive at manhood. This designation, “the mother of us all,” reflects the highest credit and the highest honor on the Church. But the Papists are fools and twice children, who expect to give us uneasiness by producing these words; for their mother is an adulteress, who brings forth to death the children of the devil; and how foolish is the demand, that the children of God should surrender themselves to her to be cruelly slain! Might not the synagogue of Jerusalem at that time have assumed such haughty pretensions, with far higher plausibility than Rome at the present day? and yet we see how Paul strips her of every honorable distinction, and consigns her to the lot of Hagar.