Who comes into God's covenant program, those born of the flesh or those born of promise?
Those born of promise, not those born of the flesh, come into God's covenant program. Ishmael, born according to fleshly effort, pictures the energy of the flesh, while the promised seed points to Christ. Every believer was promised to Christ before the foundation of the world.
Les explains that Ishmael was born in response to the wishes of the flesh, since God never told Abraham or Sarai to have a child with Hagar. That was strictly a fleshly idea, and Ishmael pictures the energy of the flesh, even as Paul uses him as an allegory in Galatians 4. By contrast, those born of promise come into God's covenant program. Les connects the singular seed to the seed of the woman in Genesis 3:15, ultimately Christ, and says every believer, whether in ancient Israel or at the end of the church age, was promised to Christ before the foundation of the world.