There are many ways God manifests Himself to this lost world. The most obvious example would be nature itself: the heavens declare the Glory of God, if you're out in the woods in spring, the birds are singing His praises, and any time of year, the world demonstrates the fine details of God's brush strokes as His world displays His mighty works. Yet, even then, there are some things that display more powerful than these. Quite simply, Obedience, Unity, and Love. I do not speak of these things in the worldly sense, but in the way in which God uses them, they are unquestionable.
Obedience. Obedience to the will of God demonstrates His great power, in that our world is in rebellion against its Creator. Nations try and enforce obedience, but can only do so through force of arms, threat of imprisonment or punishment, and by incentives that usually don't last long. No, true Obedience to the will of God is enacted by LOVE. God's people, if they worship Him in Spirit and Truth, don't obey Him because they fear punishment, for incentive, or for any such thing. Obedience is a part of their love for Him. There is no logical explanation for it, though the world labels the obedient as "zealots," "brainwashed," "strange" and other names besides. A world in rebellion against God cannot understand true obedience to God.
And this Obedience brings about unity. Why? Because there is no division in God. Man made unity is done by treaties, promises, and compacts, all easily made and just as easily broken. The natural and rebellious man's heart is wicked, self-seeking, and always looking to out maneuver the next guy. Unity in Christ, however, is supernatural. It crosses national, socio-economic, gender, ethnic and any other boundaries the world sets up. Unity in Christ is powerful, even so far as believers in Christ dying for Christ and for one another and with one another, all demonstrating the love of Christ as they do so. Unity in Christ is different than unity by worldly means; there's no obligation to enforce it, no armies to back it up, no legal disputes for international courts to sort out, it exists in love under the Kingship of Jesus Christ, in obedience to the Father, empowered by the indwelling presence of the Holy Spirit. We display God's power when we are in union with Christ and with one another.
And Love, which drives the purpose for each of these, unites in obedience. Not a worldly love, that is self-seeking, and self-fulfilling, but a sacrificial love, displayed by the actions of those who love Christ in a way that honors our King and High Priest. It is, as Jesus says, the way in which all will know we follow Him, by how we love one another. It is the driving force behind obedience: we obey because we love. It is the reason for unity: we are unified IN love. And it is the most powerful expression of our devotion to Christ: that we love the Lord with all we are and in full obedience to His will, and that we love one another in self-sacrificial love, unified in Jesus Christ.
Display the Power of God: Be obedient to His will in a rebellious world, walking in unity with all other believers, and in love, even of enemies. 1 Peter 3:8-22 Finally, all of you, have unity of mind, sympathy, brotherly love, a tender heart, and a humble mind. Do not repay evil for evil or reviling for reviling, but on the contrary, bless, for to this you were called, that you may obtain a blessing. For
“Whoever desires to love life and see good days, let him keep his tongue from evil and his lips from speaking deceit; let him turn away from evil and do good; let him seek peace and pursue it. For the eyes of the Lord are on the righteous, and his ears are open to their prayer. But the face of the Lord is against those who do evil.”
Now who is there to harm you if you are zealous for what is good? But even if you should suffer for righteousness' sake, you will be blessed. Have no fear of them, nor be troubled, but in your hearts honor Christ the Lord as holy, always being prepared to make a defense to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect, having a good conscience, so that, when you are slandered, those who revile your good behavior in Christ may be put to shame. For it is better to suffer for doing good, if that should be God's will, than for doing evil.
For Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit, in which he went and proclaimed to the spirits in prison, because they formerly did not obey, when God's patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water. Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ, who has gone into heaven and is at the right hand of God, with angels, authorities, and powers having been subjected to him.