because our testimony about Christ was confirmed in you.
6. Even as the testimony, etc. Erasmus gives a different rendering, to this effect, “that by these things the testimony of Christ was confirmed in them;” that is, by knowledge and by the word. The words, however, convey another meaning, and if they are not wrested, the meaning is easy — that God has sealed the truth of his gospel among the Corinthians, for the purpose of confirming it.
We have here the apostle's preface to his whole epistle, in which we may take notice, I. Of the inscription, in which, according to the custom of writing letters then, the name of the person by whom it was written and the persons to whom it was written are both inserted. 1.
Commenting on 1 Corinthians 1:1-9
Even as the testimony of Christ was confirmed in you. By "the testimony of Christ" is meant the Gospel of Christ, which bears a testimony to his deity, his incarnation, his obedience, sufferings, and death, his resurrection from the dead, ascension to heaven, session at God's right hand, and intercession for the saints; to redemption by his blood, justification by his righteousness, pardon and atonement...