1 Thessalonians 2:3-6, 10

For our exhortation is not of error, nor of uncleanness, nor in guile: but even as we have been approved of God to be intrusted with the gospel, so we speak; not as pleasing men, but God who proveth our hearts. For neither at any time were we found using words of flattery, as ye know, nor a cloak of covetousness, God is witness; nor seeking glory of men, neither from you nor from others, when we might have claimed authority as apostles of Christ.

Ye are witnesses, and God also, how holily and righteously and unblamably we behaved ourselves toward you that believe