In the face of the world, the church of Jesus Christ should not be seen as relishing discord but pursuing peace with all people. This is in fact the imperative set forth in Romans 12:18 - "If possible, so far as it depends on you, live peaceably with all." The context of this command falls within the framework of a larger series of precepts directed at how the church is to relate to the unbelieving world (cf. Rom.12:14-21). And among these divine requirements is the call to be peaceable rather than pugnacious. In other words, when the world observes the character and conduct of a Christian, they should see someone who is all for peaceful relations rather than just one who loves a fight.
But what does this look like practically? Romans 12:18 gives us a snapshot. "If possible, as much as it depends on you, live peaceably with all." The most important thing we need to notice about this verse is that it is qualified by two conditions. Condition number one says: "If possible...live peaceably with all." Those opening words toward peaceful relations imply something which every Christian must recognize: it may not be possible to be at peace with everyone.
Let's face it: there are people in this world (and sadly, even in the church) who make peace impossible because of either what they believe or how they behave. This means that to be at peace with such people would involve sacrificing both the truth and purity. Thus, having peace on their terms would compromise the gospel and our walk with Christ. Therefore no matter how much we may desire to be at peace with everyone, this is simply unobtainable if we're going to remain faithful to Christ and His Word.
In fact, this is where we've got to use discernment in our pursuit of peace. God has not called us to be Casper Milquetoast. We are not to be a people who are flabby and flimsy, cowards with no conviction. As we pursue peace with all people we do so governed by truth and holiness. This means that peace must never be put first in our relationships with others. We must not live by the unbiblical standard of "peace at any price." We must never go into a relationship with someone by saying, "Well, I'm just here to keep the peace."
If this is the position you take, ask yourself: "What will I have to give up in order to keep the peace?" You see, the moment we put peace as the first priority in how we relate to others, then we will ultimately sacrifice the truth of the gospel and our commitment to Christ. How is this? If peace is all you're wanting to keep in that relationship, then the terms of that relationship will be determined by whatever the other person is wanting - even if that means forfeiting truth and holiness (e.g., Gal.2:11-14). But this is not true peace. Rather it is nothing more than a cold civility that is tolerated as long as we don't say or do anything which would break the selfish terms of the other party. The spirit of authentic Christianity cannot abide under such terms (see Heb.12:14). Therefore, as a faithful servant and follower of Jesus Christ, we must accept this: it is impossible to be at peace with everyone.
But there is another condition to pursuing peace which also surfaces in Romans 12:18 - "...so far as it depends on you...live peaceably with all." The first condition focused on people and circumstances out of our control. The second condition however aims completely at what we will do. And the great point of these words is simply this: don't be the cause for discord! To say this positively - we must exhaust every avenue to live peaceably with all.
But how is this done? First, we ourselves must be at peace with God (Rom.5:1-2). True peace comes from God alone which can only be experienced through faith in Jesus Christ. Second, we must lead others to have peace with God (II Cor.5:20). Since we are at peace with God through Christ, we have the joy of being His instruments to bring others to that same peace. Third, we must help others to be at peace with one another. Where there has been division there needs to be reconciliation (Matt.5:23,24). But to seek this will require rebuking and repenting, since reconciliation implies a division made due to sin. However, if the sin is not confessed and forsaken, then there will be no peace; and hence, no reconciliation. Finally, we must prove ourselves in all things to be lovers of peace. We must contend for the truth without being contentious; disagree without being disagreeable; and confront sin without being abusive.