English Standard Version
You are witnesses, and God also, how holy and righteous and blameless was our conduct toward you believers.

American Standard Version
Ye are witnesses, and God also , how holily and righteously and unblameably we behaved ourselves toward you that believe:

Berean Study Bible
You are witnesses, and so is God, of how holy, righteous, and blameless our conduct was among you who believed.

Douay-Rheims Bible
You are witnesses, and God also, how holily, and justly, and without blame, we have been to you that have believed:

English Revised Version
Ye are witnesses, and God also, how holily and righteously and unblameably we behaved ourselves toward you that believe:

King James Bible
Ye are witnesses, and God also, how holily and justly and unblameably we behaved ourselves among you that believe:

World English Bible
You are witnesses with God, how holy, righteously, and blamelessly we behaved ourselves toward you who believe.

Young's Literal Translation
ye are witnesses -- God also -- how kindly and righteously, and blamelessly to you who believe we became,

1 Thessalonians 2:10 Additional Translations ...