+II. State the comparison.+--1. Isaac was the child of Abraham, not by natural power. Believers are children of Abraham by virtue of promise. 2. Isaac was the fruit of prayer, as well as the child of the promise. 3. Isaac's birth was the joy of his parents. Even so with reference to believers. 4. Isaac was born not after the flesh, but by the promise; not of the bondwoman, but of the free. So, believers are not under the law. 5. Isaac was no sooner born but he was mocked by Ishmael; so, it is now. 6. Isaac was the heir by promise, though thus persecuted. Even so believers. +III. How the promise hath such virtue for begetting children to God.+--1. As it is the discovery of Divine love. 2. The object of faith. 3. The ground of hope. 4. The seed of regeneration. 5. The communication of grace. 6. The chariot of the Spirit. +Inferences.+--1. _If believers are children of promise, then boasting is excluded._ 2. _Then salvation is free._ 3. _The happiness and dignity of believers--they are the children of God.--Pulpit Assistant._ Ver. 29. _On Persecution._ +I. That no privilege of the Church can exempt her from persecution.+--1. _From the consideration of the quality of the persons here upon the stage, the one persecuting, the other suffering._ (1) The persecuting--"born after the flesh." Like Hannibal, they can part with anything but war and contention; they can be without their native country, but not without an enemy. These whet the sword, these make the furnace of persecution seven times hotter than it would be. The flesh is the treasury whence these winds blow that rage and beat down all before them. (2) The suffering--"born after the Spirit." Having no security, no policy, no eloquence, no strength, but that which lieth in his innocency and truth, which he carrieth about as a cure, but it is looked upon as a persecution by those who will not be healed. "For he must appear," said Seneca, "as a fool that he may be wise, as weak that he may be strong, as base and vile that he may be more honourable." If thou be an Isaac, thou shalt find an Ishmael. 2. _From the nature and constitution of the Church which in this world is ever militant._--Persecution is the honour, the prosperity, the flourishing condition of the Church. When her branches were lopped off she spread the more, when her members were dispersed there were more gathered to her, when they were driven about the world they carried that sweet-smelling savour about them which drew in multitudes to follow them. 3. _From the providence and wisdom of God who put this enmity between these two seeds._--God's method is best. That is method and order with Him which we take to be confusion, and that which we call persecution is His art, His way of making saints. In Abraham's family Ishmael mocketh and persecuteth Isaac, in the world the synagogue persecuteth the Church, and in the Church one Christian persecuteth another. It was so, it is so, and it will be so to the end of the world.