Galatians 4:29 But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now.
In the times of Abraham, when Hagar and Sarah, the types of the two dispensations of the covenant, and Ishmael and Isaac, the figures of the two different seeds, the natural and spiritual seed of Abraham, and from scripture we know that “Hagar and Ishmael did persecute Sarah who was of the promise. What a fitting contrast, the flesh and the Promise, the natural seed and the spiritual seed.
He that was born after the flesh; which was Ishmael, who was a type, or an allegorical representation of such who were under the Sinai covenant, and were seeking for righteousness by the works of the law; as he was born after the flesh, according to the ordinary course of nature, there is nothing but flesh in them; they are without God, and Christ, and the Spirit, and have neither true faith, nor hope, nor love, not any other grace; they have no internal goodness in them; they trust in the flesh, in outward performances, in their own righteousness, and so come under the curse; for as many as trust in an arm of flesh, or are of the works of the law, are under the curse of it.
He that was born of the spiritual seed is of the promise and an allegorical representation of the covenant of Grace. who are chosen in Christ Jesus, born according to the spirit, through faith in Christ Jesus. Who trust not in works of the flesh, but in the finished work of Christ Jesus. And through no merit of our own, but by the good pleasure of God we who are redeemed owe it all to God having predestined us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will, (Ephesians 1:5)