Acts 17:10-11
"And the brethren immediately sent away Paul and Silas by night unto Berea: who coming thither went into the synagogue of the Jews. 11. These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so."
So after these believers hear Paul they searched the Scriptures (of course that was the Old Testament in those days) to see if what Paul was teaching was in accord with the Scriptures. So now let's just pick the Scriptures apart word by word,
Ephesians 3:2a
"If ye have heard of the dispensation of the grace of God..."
Now that's where we stopped in the last lesson, and we're going to stay stopped for a bit, because I'm still not quite through with what I wanted to get across so far as, "why does Paul define this dispensation of the Grace of God?" Now always remember every word that Paul writes, as well as every word that the Old Testament writers write, was inspired by the Holy Spirit. None of these writings was just the will of a person. Even when Paul in so many words says, "this is my idea" it's still inspired, and never lose sight of that. Every word is here because the Holy Spirit wants it here. So when Paul says in Romans.
Romans 11:13a
"For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles,..."