“… Abraham had two sons: the one by a bondwoman, the other by a freewoman. But he who was of the bondwoman was born according to the flesh, and he of the freewoman through promise,” (Gal. 4:22-23)
Paul went on to write that these things are symbolic of the two covenants – the old covenant law which leads to bondage and the new covenant which leads to liberty (vv. 24-26). Whose son are you? If you’re trying to serve God through rules and regulation (legalism, works), you’re living as the son of the bondwoman and living in bondage under the old covenant. If you’re serving God through faith in Jesus Christ, you’re living as the son of the freewoman and living in the liberty of the new covenant.