Christ returned to Galilee after being baptized by John the Baptist. The Holy Spirit was obviously with Jesus. The people were in awe of His teaching because He spoke with such authority. It was His custom to go to the synagogue on the Sabbath. (It is extremely important to be part of a New Testament church.)
In this passage, Christ read from the prophet Isaiah. (The synagogue at Nazareth was likely a small building, nothing like the temple in Jerusalem.) He read a brief passage (a prophecy), then handed the scroll back and sat down. All eyes were on Him. He proclaimed the prophecy fulfilled that very day. (The people had heretofore known Jesus only as Joseph’s son.)
It is important to consider both the Old & New Testaments because everything that was foretold in the Old Testament came to pass in the New Testament.
There were three offices in the Old Testament: prophet, priest and king. Christ fulfilled all three offices in His ministry. The ideal prophet, priest and king in the Old Testament was still a sinner. And they continued to be replace, as they died and the next came along. Christ is perfect in all three offices and is eternal.
Jesus was the perfect sacrifice. He both gave the sacrifice and became a one-time sacrifice for all. This is what makes Him holy and makes us unholy.
It is obvious that Christ knew the Old Testament. But by referencing Naaman, who was a Gentile, Christ was making it known that He had come for Jew and Gentile both. Likewise, we are not to dislike people who aren’t like us. Christ came for everyone.
This is what angered the congregation and provoked their wrath, that Christ was also for their enemies. They literally chased Him out of the synagogue and He disappeared among the crowd.