Summary: The rules by which we are to conduct ourselves as strangers in this world are provided in the Word of God.
“Humble yourselves, therefore, under the mighty hand of God so that at the proper time he may exalt you, casting all your anxieties on him, because he cares for you. Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour. Resist him, firm in your faith, knowing that the same kinds of suffering are being experienced by your brotherhood throughout the world. And after you have suffered a little while, the God of all grace, who has called you to his eternal glory in Christ, will himself restore, confirm, strengthen, and establish you. To him be the dominion forever and ever. Amen.” 
Civilised nations have drafted rules to guide their conduct, even in war. In the aftermath of World War II, the first three treaties previously drafted in 1864, 1906 and 1929, were updated. Nations bound themselves to abide by these protocols of war and further agreed to a set of rules for humanitarian treatment of prisoners of war, for treatment of the wounded and for handling civilian non-combatants. These rules are commonly known as the Geneva Conventions of War. Modern wars, often referred to as limited engagements, tend to disregard these conventions, though those warring against the western powers demand that their own people be treated in accordance with these protocols.
Christians are engaged in a protracted war with the ruler of this world. Those dark powers aligned with the evil one are merciless and without pity. They disregard all pleas from the wounded or those caught up in the war. However, we who are identified with the King of kings and the Lord of lords are bound by His Word to conduct ourselves according to the rules of engagement that He has given us. It will be to our benefit to know His will and to ensure that we do His will. These, then, are the rules of engagement given by the Son of God.
CONTEXT —Believers are engaged in a conflict; this is not a brief conflict—it began before the fall of our first parents and has continued unabated since that time. A powerful angel, once known as Day Star [see ISAIAH 14:12], rebelled against the True and Living God. Because of His beauty, he grew proud and determined in his heart to displace the Lord God from His eternal throne [see ISAIAH 14:13, 14]. He was cast out of heaven and to the earth [see EZEKIEL 28:12-19]; there, he was instrumental in deceiving our first mother and plunging the world into its present condition of sin and ruin. He is set in opposition to God and to all who seek to serve the Lord God of Heaven and earth. He is the enemy of the soul, slandering the saints before the Most High [cf. JOB 1:6-12; 2:1-7]. For the moment, he functions as “the ruler of this world” [JOHN 12:31] and “the god of this world” [2 CORINTHIANS 4:4], though his destiny is destruction when he shall at last be cast into the lake of fire [REVELATION 20:9, 10]. The American President may fight wars on a timetable; but this is a war that must be fought until victory is achieved.
We do believers no favour when we fail to inform them that because they are born from above, they will be thrust into battle the remainder of their lives. They did not choose to fight; but they will be forced to fight. Paul warns believers that “We do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places” [EPHESIANS 6:12].
Moreover, the fight is not conducted with weapons of metal or explosives. We are taught, “The weapons of our warfare are not of the flesh but have divine power to destroy strongholds. We destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ” [2 CORINTHIANS 10:4, 5].
If we are Christians, we will fight. Though we may attempt to absent ourselves from the battle, if we are children of the Living God, we cannot excuse ourselves from the conflict. The battle will come to us; we cannot flee from it. Consequently, the rules of engagement Peter will now deliver are directed to all believers. I understand very well that he has been addressing the elders in the first four verses of this chapter. However, listen to this fifth verse as he transitions to addressing all within the assembly. “You who are younger, be subject to the elders. Clothe yourselves, all of you, with humility toward one another, for ‘God opposes the proud but gives grace to the humble’” [1 PETER 5:5].
Underscore the initial phrase of the final sentence of this verse. “Clothe yourselves, all of you, with humility toward one another.” When Peter writes “all of you,” he ensures that none can avoid the application of what he is about to write. The admonitions that follow are for all saints. The plea is for each of us to submit to those who are wise, whom God has appointed to oversee the congregation. Watch their lives; follow their example. Accept their decisions; don’t attempt to second-guess them. Respect their years of experience and honour their seasoned lives.