Paul’s point is not merely that there is a temporary similarity between the heir and the servant, since both are under the same tutorial of the Mosaic law; but Paul goes on to show that the rightful heir turns around and provides an undeserved inheritance to the Lord’s servants.
In its misperceived, perverted form, the promise could not be good news to all people, for it was enjoined to commands that had been given to some people. Once the universal scope and offer of the gospel was hidden by this heresy, Paul was swift and courageous to correct the error.
The more frequently and deeply people converse with one another, the richer language becomes. Ironically, this richness and complexity of language also leads to the comprehensibility of ideas. Comprehensibility, then, is surprisingly made subject to a kind of complexity.