'Virtues' in the Bible
This is our [reason for] proud confidence: our conscience testifies that we have conducted ourselves in the world [in general], and especially toward you, with pure motives and godly sincerity, not in human wisdom, but in the grace of God [that is, His gracious lovingkindness that leads people to Christ and spiritual maturity].
We are not commending ourselves to you again, but are giving you an occasion to be [rightfully] proud of us, so that you will have an answer for those who take pride in [outward] appearances [the virtues they pretend to have] rather than what is [actually] in heart.
But you are a chosen race, a royal priesthood, a consecrated nation, a [special] people for God’s own possession, so that you may proclaim the excellencies [the wonderful deeds and virtues and perfections] of Him who called you out of darkness into His marvelous light.