He overcame the Jews. By this it appeareth to what use that ability which Apollos had (in that he was mighty in the Holy Scriptures) did serve; to wit, because he had a strong and forcible proof to reprove and overcome the enemies withal. Also, the state of the disputation is briefly set down, that Jesus is Christ. For this was out of question among the Jews, that Christ was promised to be the deliverer; but it was a hard matter to persuade them that Jesus, the Son of Mary, was this Christ, through whom salvation was offered. Therefore, it was expedient for Apollos so to dispute concerning the office of Christ, that he might prove that the testimonies of the Scripture were fulfilled in the Son of Mary; and that he might thereby gather that he was Christ. Also, this place doth testify, that the Scripture is profitable not only to teach, but also to break the obstinacy of those which do not obey and follow willingly. For our faith should not otherwise be firm enough, unless there were an evident demonstration extant there of those things which are necessary to be known for salvation. Surely, if the law and the prophets had so great light, that Apollos did thereby prove manifestly that Jesus is Christ, as if he did point out the matter with his finger, the adding of the gospel must bring this to pass at least, that the perfect knowledge of Christ may be let [sought] from the whole Scripture. Wherefore it is detestable blasphemy against God in that the Papists say, that the Scripture is dark and doubtful. For to what end should God have spoken, unless the plain and invincible truth should show itself in his words? And whereas they infer, that we must stand to the authority of the Church, and they are not to dispute with heretics out of the Scriptures; their cavil is sufficiently refuted by Luke. For, seeing there was nothing more stubborn than the Jews, we need not to fear but that those weapons whereto Apollos trusted, and overcame them, shall suffice us against all heretics, seeing that by them we get the victory of the devil, the prince of all errors.

For he mightily convinced the Jews - He did it by strong arguments; he bore down all opposition, and effectually silenced them.
And that publicly - In his public preaching in the synagogue and elsewhere.
Showing by the scriptures - Proving from the Old Testament. Showing that Jesus of Nazareth corresponded with the account of the Messiah given by the prophets. See the notes on John 5:39.
That Jesus was Christ - See the margin. That Jesus of Nazareth was the Messiah.

He mightily convinced the Jews - Ευτονως διακατηλεγχετο; He vehemently confuted the Jews; and that publicly, not in private conferences, but in his public preaching: showing by the scriptures of the Old Testament, which the Jews received as divinely inspired, that Jesus, who had lately appeared among them, and whom they had crucified, was the Christ, the promised Messiah, and that there was salvation in none other; and that they must receive him as the Messiah, in order to escape the wrath to come. This they refused to do; and we know the consequence. Their city was sacked, their temple burnt, their whole civil and religious polity subverted, more than a million of themselves killed, and the rest scattered over the face of the earth.
1. The Christian religion did not hide itself in corners and obscure places at first, in order, privately, to get strength, before it dared to show itself publicly. Error, conscious of its weakness, and that its pretensions cannot bear examination, is obliged to observe such a cautious procedure. With what caution, circumspection, and privacy, did Mohammed propose his new religion! He formed a party by little and little, in the most private manner, before he ventured to exhibit his pretensions openly. Not so Christianity: it showed itself in the most public manner, not only in the teaching of Christ, but also in that of the apostles. Even after the crucifixion of our Lord, the apostles and believers went to the temple, the most public place; and in the most public manner taught and worked miracles. Jerusalem, the seat of the doctors, the judge of religion, was the first place in which, by the command of their Lord, the disciples preached Christ crucified. They were, therefore, not afraid to have their cause tried by the most rigid test of Scripture; and in the very place, too, where that Scripture was best understood.
2. When the same apostles. carried this Gospel to heathen countries, did they go to the villages, among the less informed or comparatively ignorant Greeks, in order to form a party, and shield themselves by getting the multitude on their side? No! They went to Caesarea, to Antioch, to Thessalonica, to Athens, to Corinth, to Ephesus; to the very places where learning flourished most, where sciences were best cultivated, where imposture was most likely to be detected, and where the secular power existed in the most despotic manner, and could at once have crushed them to nothing could they have been proved to be impostors, or had they not been under the immediate protection of Heaven! Hence it is evident that these holy men feared no rational investigation of their doctrines, for they taught them in the face of the most celebrated schools in the universe!
3. They preached Christ crucified in Jerusalem, where it was the most solemn interest of the Jews to disprove their doctrine, that they might exculpate themselves from the murder of Jesus Christ. They preached the same Christ, and the vanity of idolatry, in Athens, in Corinth, and in Ephesus, where idolatry existed in the plenitude of its power; and where all its interests required it to make the moat desperate and formidable stand against those innovators. What but the fullest confidence of the truth of what they preached, the fullest conviction of the Divinity of their doctrine, and the supernatural influence of God upon their souls, could ever have induced these men to preach Christ crucified, either at Jerusalem, or at Athens? I scruple not to assert that the bold, public manner in which the apostles preached the Gospel, among the Jews and Greeks, is a most incontestable proof of the conviction they had of its truth; and the success with which they were favored is a demonstration that what they preached as truth God proved to be the truth, by stretching forth his hand to heal, and causing signs and wonders to be wrought in the name of the holy child Jesus. This is an additional proof of the sincerity of the apostles, and of the truth of Christianity. If Paul and Peter, Barnabas and Silas, had not had the fullest persuasion that their doctrine was of God, they would never have ventured to propose it before the Sanhedrin in Jerusalem, the literati of Corinth, and the Stoics and inexorable judges of the Areopagus at Athens.
4. We may be surprised to find that, even among the Jews as well as the Gentiles, there were persons who used curious arts. Those were inexcusable; these were to be pitied. Blind as every man is by nature, yet he is conscious that without supernatural assistance he can neither secure the good he needs, nor avoid the evil he fears: therefore, he endeavors to associate to himself the influence of supernatural agents, in order to preserve him in safety, and make him happy. Thus forsaking and forgetting the fountain of living water, he hews out to himself cisterns that can hold no water. The existence of magical arts and incantations, whether real or pretended, prove the general belief of the existence of a spiritual world, and man's consciousness of his own weakness, and his need of supernatural help. When shall the eye be directed solely to Him from whom alone true help can come, by whom evil is banished, and happiness restored!

For he mightily convinced the Jews,.... His reasoning was so strong and nervous, his arguments so weighty and powerful, and the passages he produced out of the Old Testament so full and pertinent, that the Jews were not able to stand against him; they could not object to the texts of Scripture he urged, nor to the sense he gave of them, nor answer the arguments founded upon them; he was an overmatch for them; they were refuted by him over and over, and were confounded to the last degree:
and that publicly, in their synagogue, before all the people; which increased their shame and confusion; and was the means of spreading the Gospel, of bringing others to the faith of it, and of establishing them in it, who had already received it: showing by the Scriptures; of the Old Testament, which the Jews received and acknowledged as the word of God:
that Jesus was Christ; or that Christ, that Messiah, which these Scriptures spoke of, whom God had promised, and the church of God expected; and which was the main thing in controversy between the Jews and the Christians, as it still is.

For he mightily convinced the Jews--The word is very strong: "stoutly bore them down in argument," "vigorously argued them down," and the tense in that he continued to do it, or that this was the characteristic of his ministry.
showing by the scriptures that Jesus was Christ--Rather, "that the Christ (or Messiah) was Jesus." This expression, when compared with Acts 18:25, seems to imply a richer testimony than with his partial knowledge he was at first able to bear; and the power with which he bore down all opposition in argument is that which made him such an acquisition to the brethren. Thus his ministry would be as good as another visitation to the Achaian churches by the apostle himself (see 1-Corinthians 3:6) and the more as, in so far as he was indebted for it to Priscilla and Aquila, it would have a decidedly Pauline cast.