Finally - As the last direction, or as general counsel in reference to your conduct in all the relations of life. The apostle had specified most of the important relations which Christians sustain, 1 Peter 2:13-25; 1 Peter 3:1-7; and he now gives a general direction in regard to their conduct in all those relations.
Be ye all of one mind - See the notes at Romans 12:16. The word used here (ὁμόφρων homophrōn) does not elsewhere occur in the New Testament. It means, of the same mind; like-minded; and the object is to secure harmony in their views and feelings.
Having compassion one of another - “Sympathizing,” (συμπαθεῖς sumpatheis;) entering into one another’s feelings, and evincing a regard for each other’s welfare. See the notes at Romans 12:15. Compare 1 Corinthians 12:26; John 11:35. The Greek word used here does occur not elsewhere in the New Testament. It describes that state of mind which exists when we enter into the feelings of others as if they were our own, as the different parts of the body are affected by that which affects one. See the notes at 1 Corinthians 12:26.
Love as brethren - Margin, “loving to the;” that is, the brethren. The Greek word (φιλάδελφος philadelphos) does not elsewhere occur in the New Testament. It means loving one’s brethren; that is, loving each other as Christian brethren - Robinson, Lexicon. Thus, it enforces the duty so often enjoined in the New Testament, that of love to Christians as brethren of the same family. See the notes at Romans 12:10. Compare Hebrews 13:1; John 13:34.
Be pitiful - The word used here (εὔσπλαγχνος eusplangchnos) occurs nowhere else in the New Testament, except in Ephesians 4:32, where it is rendered “tender-hearted.” See the notes at that verse.
Be courteous - This word also φιλόφρων (philophrōn) occurs nowhere else in the New Testament. It means “friendly-minded, kind, courteous.” Later editions of the New Testament, instead of this, read (ταπεινόφρονες tapeinophrones) of a lowly or humble mind. See Hahn. The sense is not materially varied. In the one word, the idea of “friendliness” is the one that prevails; in the other, that of “humility.” Christianity requires both of these virtues, and either word enforces an important injunction. The authority is in favor of the latter reading; and though Christianity requires that we should be courteous and gentlemanly in our treatment of others, this text can hardly be relied on as a prooftext of that point.