We must pursue peace and purity to finish the Christian race: Stay on course (12:14)!
The course entails the two great commandments. Pursuing “peace with all men” is the second commandment, to “love your neighbor as yourself” (Matt. 22:39). To pursue “the sanctification without which no one will see the Lord” is the first commandment, to “love the Lord your God with all your heart, and with all your soul, and with all your mind” (Matt. 22:37). Jesus links these two themes (in reverse order) in the Sermon on the Mount: “Blessed are the pure in heart, for they shall see God. Blessed are the peacemakers, for they shall be called sons of God” (Matt. 5:8, 9).
The link between pursuing peace and sanctification shows that we must not pursue peace at any cost. As Paul puts it (Rom. 12:18), “If possible, so far as it depends on you, be at peace with all men.” His words imply the reality of living in this fallen world, that sometimes it is not possible to be at peace with everyone. Sometimes the other person clings to bitterness and hatred, and you can’t do anything more than you’ve done to be reconciled. At other times, to make peace would require compromising obedience to God, either morally or doctrinally. You can’t sacrifice personal holiness or commitment to God’s truth for the sake of peace. But, whenever you can do so without compromise, the race set before us includes pursuing both peace with others and purity before God.
More teaching here or copy and paste this link https://bible.org/seriespage/lesson-47-perseverance-peace-and-purity-hebrews-1212-14