There's a clear religious limit on celebrating nations. Nations can usurp God as the object of our reverence and awe. Even moderate forms of nation worship can become spiritually problematic.
I allowed an American flag on my pulpit, but one of my teachers considered this an act of idolatry. I disagreed, but he made a powerful point. The most soaring divine caution against nation worship comes from the Book of Isaiah: "All nations before him are as nothing and they are counted to him less than nothing and vanity. . . . It is he that sitteth upon the circle of the earth and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in: That bringeth the princes to nothing; he maketh the judges of the earth as vanity . . . Hast thou not known? Hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is weary? There is no searching of his understanding. He giveth power to the faint; and to them that have no might he increaseth strength. Even the youths shall faint and be weary, and the young men shall utterly fall: But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint." (Isaiah 40:17, 22-23, 28-31) As a proud American grasshopper, let me say that Isaiah was right -- but not completely. America has always mixed a large dose of humility and reverence for God into its national pride.
You can see this in nearly everything Lincoln ever wrote. His Proclamation for a National Day of Fasting Humiliation and Prayer in 1863 notes: "We have been the recipients of the choicest bounties of heaven. We have been preserved, these many years, in peace and prosperity. We have grown in numbers wealth and power, as no other nation has ever grown. But we have forgotten God. We have forgotten the gracious hand which preserved us in peace, and multiplied and enriched and strengthened us; and we have vainly imagined, in the deceitfulness of our hearts, that all these blessings were produced by some superior wisdom and virtue of our own."
Even at the peak of the Civil War, Lincoln was able to embrace the God-given sanctity of the lives of all the war dead. Someone complained to Lincoln about mentioning the number of Confederate casualties: "Who are they to us, Mr. President?" he asked. Lincoln replied: "Thank God, the world is larger than your heart." America at its best has a heart as big as the world. It's a welcoming heart, and this July 4, I'll be toasting our historic compassion toward generations of immigrants who, like my ancestors, have found a home in this great land. At the Statue of Liberty, the America I love invites the world to partake in our freedom: "Not like the brazen giant of Greek fame. With conquering limbs astride from land to land; Here at our sea-washed, sunset gates shall stand A mighty woman with a torch, whose flame Is the imprisoned lightning, and her name Mother of Exiles. From her beacon-hand Glows world-wide welcome; her mild eyes command The air-bridged harbor that twin cities frame. 'Keep, ancient lands, your storied pomp!' cries she with silent lips. 'Give me your tired, your poor, Your huddled masses yearning to breathe free, The wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!' " ("The New Colossus," by Emma Lazarus) America is not just a land of spoiled grasshoppers, but a place with a spiritual soul. Her soul may be corrupted by selfishness, xenophobia and racism -- but not her essence. It is America the beautiful and America the humble I will celebrate this July 4 and always.