At the beginning of chapter 53 he foretold that not all would believe them. Therefore, the fact that not all believed the Gospel does not refute that the evangelists were sent by God and proclaim the truth.
For this was foretold by God. Blessed Theodoret writes: "Having brought forward the testimony about the preachers, the Apostle continues in the form of a question: 'But have not all obeyed the Gospel?'
"Then, in the form of an answer, he brings forward the words of the Prophet."
Saint Chrysostom depicts this more fully: "The Jews again raised a new objection, saying: if the Apostles were sent by God, then all ought to have obeyed them.
"Notice Paul's prudence, how he proves that the very thing which caused disturbance ought to remove disturbance and anxiety. What troubles you, O Jew, after so many and such weighty testimonies, and after their confirmation by the facts themselves?
"Is it that not all obeyed the Gospel? This very fact, that not all obey, together with the other proofs, is enough to convince you of the truth of what is preached.
"For the Prophet also foretold this from of old. What are you saying, he asks? That not all obeyed the Gospel? But Isaiah long ago foretold even this.
"More exactly, he foretold not this alone, but something much greater. You make it an accusation that not all obeyed. Isaiah says still more. What exactly? 'Lord, who has believed our report?'"
Let us add from Blessed Theophylact: "Here the word 'who' is used instead of 'few.' That is, few believed what they heard from us."
The prophetic passage is taken from the fifty-third chapter of holy Isaiah, where he portrays the sufferings and death of Christ the Savior so vividly, as though they were taking place before his eyes.
At the very beginning of this portrayal he poses the question: "Lord, who has believed our report?" Here he assumes the person of the Apostles and speaks thus on their behalf.
In reality this is exactly what happened. The Apostles preached Christ crucified, as the Apostle Paul testifies. For the Jews this was a scandal, and for the Greeks folly (see 1 Cor. 1:23).
For this reason both resisted believing. Some believed, but few, namely the chosen. Therefore the question was fitting in their soul: Lord, how few believe what we place in their ears.
Who, who believes? Foreseeing this, the Prophet cried out, as though in their person, before depicting the sufferings and death of the Lord and Savior: who has believed?
It is closer to the subject of verses 15 and 16 to read the words "But have not all obeyed the Gospel?" as a question. In these verses the Apostle answers the proposed question: were the preachers not sent?
They were sent, he says, and they preach. The fact that not all listen should not cast doubt on the fact that they truly were sent.
If these words are read without a question, they will contain an unanswerable accusation against the Jews, the subject of the whole section (see Rom. 10:14-21). Therefore this too is fitting, but it somewhat disturbs the structure of the discourse.
In the answers to "Have they not heard?" and to "Did Israel not understand?" only prophetic words are cited, without attaching an accusation. But here an accusation would stand.
Yet the Apostle's aim is not to accuse them openly to their face. It is that the Jews themselves should pronounce the accusation against themselves on the basis of what he says.