Even as the testimony of Christ was confirmed in you:
Berean Study Bible (BSB) - 1 Corinthians 1:6 >because our testimony about Christ was confirmed in you.
Textus Receptus (TR) - 1 Corinthians 1:6 >καθὼς τὸ μαρτύριον τοῦ Χριστοῦ ἐβεβαιώθη ἐν ὑμῖν·