I think most of us, when first reading this passage, can be excused for cocking our heads to the side and wondering out loud, “Could you be any more esoteric, Paul?” What exactly is he driving at with this comment about someone’s last will and testament? People change their wills all the time, don’t they? At least before they die, so why bring this up here? It seems, that Paul wants to again make the point that God had made a promise to Abraham, that all nations would be blessed through Abraham. And so, this discussion about a will is really about the ultimate provider of salvation – the law, or faith.
Some politicians have called entire segments of the media “Fake News” simply because they don’t want people to hear the truth; most politicians know that the quickest way to discredit a message is to discredit the messenger. Most criminal defense attorneys know the same thing, and actively try to persuade the people of the jury that the witness on the stand cannot be trusted; often it is just because the witness has an undesirable event in their past. It’s an incredibly effective strategy; most people would clearly not want to be treated or judged in this way, but they are quick to judge another person as untrustworthy simply because that person has been found wanting. This is, effectively, what Paul had to deal with.