CLAIM: Paul says that 430 years passed between the time of Abraham to Moses. However, Abraham lived in roughly 2,000 BC, and Moses lived in roughly 1440 BC. This would mean that Paul’s chronology was off by over a hundred years.
RESPONSE: This objection is based on a misunderstanding of the text. Paul is not referring to the length of time between Abraham and Moses. Instead, he is referring to the amount of time that the Jews languished in slavery, which is confirmed in the Septuagint’s mention of 430 years (Ex. 12:40). Others argue that Paul is not referring to the giving of the covenant to Abraham but to the ratifying of the covenant under Jacob. They reach this conclusion, because the text specifically speaks of the covenant “previously ratified by God” (v.17).
 Stott writes, “A period of 430 years is mentioned (verse 17), which refers not to the time between Abraham and Moses, but to the duration of the bondage in Egypt (Ex. 12:40; cf. Gn. 15:13; Acts 7:6).” Stott, John R. W. The Message of the Galatians: John R.W. Stott. Leicester, England: Inter-Varsity, 1986. 86. Ben Witherington writes, “This calculation is surely based on Ex. 12:40 LXX which says that the Israelites dwelled in Egypt for this length of time.” Witherington, Ben. Grace in Galatia: a Commentary on St. Paul’s Letter to the Galatians. Grand Rapids, MI: W.B. Eerdmans Pub., 1998. 245.