In "Doctrinal Discussion" Jason Lindahl writes:

A friend was describing conditions at his former place of employment. The picture was not rosy — bad attitudes, squabbles, childish behavior. The sad thing, he lamented in conclusion, was that the people who claimed to be Christians were the hardest with which to work. Those who made no claims to grace were, for the most part, the preferred co-workers. Too often, such an accusation has been repeated. “Christians” may be faithful at church attendance three times a week, be diligent in tithing and even verbal witnessing for Jesus, and wear three-quarter-length sleeves with fashionable ease; but whatever happened to graciousness, kindness, and consideration for others? What place is there for a chip on a Christian's shoulder, or a bite in a Christian's speech? Why doesn't anyone like to work with you, Christian? Are you sure it is just persecution?

Source: Building Christian Relationships: Adult Teacher's Insights, page 67.

In "God's Word for Today" Gordon Snider writes:

Peter began by addressing the Christian's attitude toward fellow Christians. He was addressing believers who were living under persecution and the stress that creates in relationships. It is easy to be critical and defensive when you are constantly under attack. Peter urged his readers to resist that temptation. The focus should be on what Christians have in common, and not on their differences (“be . . . of one mind”). Attitudes of sympathy, compassion, and consideration were to be prominent. And if they are, Peter reasoned, it will affect the use of your tongue. Words of blessing will be more common than words of criticism. Your words will bring peace instead of division; healing rather than hurt. Your speech will be marked by transparency rather than deception. Verse 12 suggests clearly that such a person is the one who finds favor in the eyes of God.

Source: Building Christian Relationships: Adult Teacher's Insights, page 65.