Summary: Christians are commanded to demonstrate perfect courtesy toward all people. We are called to speak the truth in love; this means that we are to be gentle and gracious toward those who speak ill of us or who attempt to injure us.
“Remind [the believers] to be submissive to rulers and authorities, to be obedient, to be ready for every good work, to speak evil of no one, to avoid quarrelling, to be gentle, and to show perfect courtesy toward all people. For we ourselves were once foolish, disobedient, led astray, slaves to various passions and pleasures, passing our days in malice and envy, hated by others and hating one another. But when the goodness and loving kindness of God our Saviour appeared, he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit, whom he poured out on us richly through Jesus Christ our Saviour, so that being justified by his grace we might become heirs according to the hope of eternal life. The saying is trustworthy, and I want you to insist on these things, so that those who have believed in God may be careful to devote themselves to good works. These things are excellent and profitable for people.” 
Have you ever heard someone say something like “I'm sick of political correctness”; and then, attempting to prove the point, that same individual uses hurtful epithets to describe other people? Or perhaps you have noticed that those who often decry what they call “hate speech” are the first to label someone else a “bigot?” So very often, those who claim to be most offended by others are quick to label others using hateful names, such as “racist,” “sexist” or “homophobic.” It leads me to ask, “Whatever happened to courtesy? More correctly, perhaps we should ask, “Whatever happened to civility-in public discourse?”
That is the question Gina Dalfonzo explored in an article, “The Lost Virtue of Courtesy,” that can be found at Christianity Today Online.  In that article, Ms. Dalfonzo notes that in Mere Christianity, C. S. Lewis described courtesy as the idea “that no one give any kind of preference to himself.” “Courtesy,” Lewis wrote, is one hallmark of a “fully Christian society.” Underscore that thought, Courtesy is one hallmark of a fully Christian society. A society that lacks courtesy cannot be said to be Christian. For some years, secularists and modernist ministers have insisted that we now live in a “post-Christian” era. If the fact that people take themselves far too seriously and if generalised rudeness witnessed on a daily basis is any indication, then we would be hard-pressed to claim that ours is a Christian society.
I fear that the attitudes that now characterise this dying world have been adopted to a large extent by the professed people of God. We have made violence our entertainment and biting sarcasm our amusement. We have become so touchy that every niggling slight, real or imagined, ignites our outrage. We no longer teach our youth to ignore slights, permitting them to continue to throw temper tantrums in order to get their way. Universities and colleges no longer challenged students to think or to hear differing views. Rather, these institutions have forsaken the mandate to provide higher education, becoming glorified nursery schools where students are indoctrinated and treated as precious snowflakes. The anonymity of social media permits us to slander and castigate everyone, even those deserving our respect. Tragically, Christians are increasingly undifferentiated from the fallen world in which we live. We act this way despite being cautioned against such actions in the Word of God.
COURTESY IS A CHRISTIAN VIRTUE — “Remind [the believers] to be submissive to rulers and authorities, to be obedient, to be ready for every good work, to speak evil of no one, to avoid quarrelling, to be gentle, and to show perfect courtesy toward all people.” When the Apostle writes, “remind the believers,” it indicates that we should know what is coming already. Christian courtesy should be taught from earliest days in this holy Faith.
Christians should be godly in speech and in conduct. Throughout the New Testament are multiple admonitions for how Christians are to conduct themselves before the watching world. Our deportment and our speech reveals the reality of the work that the Spirit of God is doing in our lives. The passage I wish to cite is admittedly extended, but it does exemplify the instruction concerning conduct and speech expected of believers. Paul instructs the Colossian Christians, “If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. Set your minds on things that are above, not on things that are on earth. For you have died, and your life is hidden with Christ in God. When Christ who is your life appears, then you also will appear with him in glory.
“Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. On account of these the wrath of God is coming. In these you too once walked, when you were living in them. But now you must put them all away: anger, wrath, malice, slander, and obscene talk from your mouth. Do not lie to one another, seeing that you have put off the old self with its practices and have put on the new self, which is being renewed in knowledge after the image of its creator. Here there is not Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave, free; but Christ is all, and in all.