Contradiction with Romans 9:8
Romans 9:8 suggests that not all children of Abraham are considered children of God, contrasting Galatians 4:28, which aligns believers with Isaac as children of promise.
Romans 9:8: That is, They which are the children of the flesh, these [are] not the children of God: but the children of the promise are counted for the seed.
Contradiction with John 8:39
John 8:39 indicates that merely being descendants of Abraham doesn't make one a true child of Abraham, conflicting with the notion in Galatians 4:28 that believers inherit the promise like Isaac.
John 8:39: They answered and said unto him, Abraham is our father. Jesus saith unto them, If ye were Abraham's children, ye would do the works of Abraham.
Contradiction with Galatians 3:7
Galatians 3:7 emphasizes faith as the defining characteristic of the children of Abraham, whereas Galatians 4:28 uniquely parallels believers with Isaac directly.
Galatians 3:7: Know ye therefore that they which are of faith, the same are the children of Abraham.
Contradiction with John 3:6
John 3:6 highlights the separation between flesh and spirit, implying a distinction in birthright that complicates Galatians 4:28's identification with Isaac through faith.
John 3:6: That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
Contradiction with Romans 4:13
Romans 4:13 declares the promise was through faith, not the law or ancestry, which nuances the straightforward claim in Galatians 4:28 about being children of promise akin to Isaac.
Romans 4:13: For the promise, that he should be the heir of the world, [was] not to Abraham, or to his seed, through the law, but through the righteousness of faith.