Isaiah calls the Church barren because her children are born without effort by the Word of faith through the Spirit of God. It is a matter of birth, not of exertion. The believer too works, but not in an effort to become a son and an heir of God. He is that before he goes to work. He is born a son and an heir. He works for the glory of God and the welfare of his fellowmen. VERSE 28. Now we, brethren, as Isaac was, are the children of promise. The Jews claimed to be the children of God because they were the children of Abraham. Jesus answered them, John 8:39, 40, “If ye were Abraham’s children, ye would do the works of Abraham. But now ye seek to kill me, a man that hath told you the truth.” And in verse 42: “If God were your Father, ye would love me.” In other words: “You are not the children of God. If you were, you would know and love me. Brothers born and living together in the same house recognize each other. You do not recognize me. You are of your father, the devil.” We are not like these Jews, the children of the bondwoman, the Law, who were cast out of the house by Jesus. We are children of the promise like Isaac, born of grace and faith unto an everlasting inheritance. VERSE 29. But as that he that was born after the flesh persecuted him that was born after the Spirit, even so it is now. This is a cheering thought. We who are born of the Gospel, and live in Christ, and rejoice in our inheritance, have Ishmael for our enemy. The children of the Law will always persecute the children of the Gospel. This is our daily experience. Our opponents tell us that everything was at peace before the Gospel was revived by us. Since then the whole world has been upset. People blame us and the Gospel for everything, for the disobedience of subjects to their rulers, for wars, plagues, and famines, for revolutions, and every other evil that can be imagined. No wonder our opponents think they are doing God a favor by hating and persecuting us. Ishmael will persecute Isaac. We invite our opponents to tell us what good things attended the preaching of the Gospel by the apostles. Did not the destruction of Jerusalem follow on the heels of the Gospel? And how about the overthrow of the Roman Empire? Did not the whole world seethe with unrest as the Gospel was preached in the whole world? We do not say that the Gospel instigated these upheavals. The iniquity of man did it. Our opponents blame our doctrine for the present turmoil. But ours is a doctrine of grace and peace. It does not stir up trouble. Trouble starts when the people, the nations and their rulers of the earth rage and take counsel together against the Lord, and against His anointed. (Psalm 2.) But all their counsels shall be brought to naught. “He that sitteth in the heavens shall laugh: the Lord shall have them in derision.” (Psalm 2:4.) Let them cry out against us as much as they like. We know that they are the cause of all their own troubles.