That is the story told by his grand-nephew, Henry Augustus Muhlenberg, in his 1849 book, The Life of Major-General Peter Muhlenberg of the Revolutionary Army, and retold in Thomas Buchanan Read's 1862 poem, The Wagoner of the Alleghanies. A Poem of the Days of Seventy-six, in two of the sections of the larger poem titled "The Rising" and "The Brave at Home," which have since been often extracted and combined together into one poem called "The Patriot Pastor, or, The Rising in 1776." The original Wagoner poem is includes a larger theme of the love between Edgar, a heroic Army volunteer, and Esther, his beloved, who are said to have been present on this stirring occasion, and the fires of their ardor compliment the flames of revolutionary passion told in the tale.
Many points of the story have been disputed from the date of his sermon, to the sermon matter and even the dramatic unveiling of his uniform in the midst of the service, as well as the recruits attributed to this event. Nevertheless, it is unquestioned that Peter Muhlenberg was a Lutherand and Anglican minister, a member of the Committee of Safety and Correspondence, who resigned his pulpit to serve the Continental Army, and did so with distinction. A statue in the U.S. Capitol building commemorates this patriot-pastor today.
His brother Frederick, also a Lutheran minister, who once inclined to the view that to oppose King George III was rebellion and treason, but later joined with his brother Peter in the service of the new nation (he was the first Speaker of the U.S. House of Representatives and the first signer of the Bill of Rights), quoted Peter's account of why he left the ministry to serve his country: "I am a clergyman, it is true, but I am also a member of society as well as the poorest layman, and my liberty is as dear to me as to any man. Shall I then sit still, and enjoy myself at home, when the best blood of the continent is spilling? Heaven forbid it! Do you think if America should be conquered I should be safe? Far from it. And would you not sooner fight like a man than die like a dog? The cause is just and noble. Were I a bishop, even a Lutheran one, I should obey without hesitation; and, so far from thinking that I am wrong, I am convinced it is my duty so to do,—a duty I owe to my God and to my country."
Without further ado (although I recommend reading the full Wagoner of the Alleghanies, as well as critiques of the common historical account, to gain a fuller view of the story) here is Thomas Buchanan Read's The Patriot-Pastor, or The Rising in 1776:
Out of the North the wild news came,
Far flashing on its wings of flame,
Swift as the boreal light which flies
At midnight through the startled skies.
And there was tumult in the air,
The fife’s shrill note, the drum’s loud beat,
And through the land everywhere
The answering tread of hurrying feet;
While the first oath of Freedom’s gun
Came on the blast from Lexington;
And Concord, roused, no longer tame,
Forgot her old baptismal name,
Made bare her patriot arm of power,
And swelled the discord of the hour.
Within its shade of elm and oak
The church of Berkely Manor stood;
There Sunday found the rural folk,
And some esteemed of gentle blood.
In vain their feet with loitering tread
Passed ‘mid the graves where rank is naught;
All could not read the lesson taught
In that republic of the dead.
How sweet the hour of Sabbath talk,
The vale with peace and sunshine full
Where all the happy people walk,
Decked in their homespun flax and wool!
Where youth’s gay hats with blossoms bloom;
And every maid with simple art,
Wears on her breast, like her own heart,
A bud whose depths are all perfume;
While every garment’s gentle stir
Is breathing rose and lavender.
The pastor came; his snowy locks
Hallowed his brow of thought and care;
And calmly, as shepherds lead their flocks,
He led into the house of prayer.
The pastor rose; the prayer was strong;
The psalm was warrior David’s song;
The text, a few short words of might,-
“The Lord of hosts shall arm the right!”
He spoke of wrongs too long endured,
Of sacred rights to be secured;
Then from his patriot tongue of flame
The startling words for Freedom came.
The stirring sentences he spake
Compelled the heart to glow or quake,
And, rising on his theme’s broad wing,
And grasping in his nervous hand
The imaginary battle brand,
In face of death he dared to fling
Defiance to a tyrant king.
Even as he spoke, his frame, renewed
In eloquence of attitude,
Rose, as it seemed, a shoulder higher;
Then swept his kindling glance of fire
From startled pew to breathless choir;
When suddenly his mantle wide
His hands impatient flung aside,
And, lo, he met their wondering eyes
Complete in all a warrior’s guise.
A moment there was awful pause, -
When Berkeley cried, “Cease, traitor! Cease!
God’s temple is the house of peace!”
The other shouted, “Nay, not so,
When God is with our righteous cause;
His holiest places then are ours,
His temples are our forts and towers,
That frown upon the tyrant foe;
In this, the dawn of Freedom’s say,
There is a time to fight and pray!”
And now before the open door-
The warrior priest had ordered so-
The enlisting trumpet’s sudden roar
Rang through the chapel, o’er and o’er,
Its long reverberating blow
So loud and clear, it seemed the ear
Of dusty death must wake and hear.
And there the startling drum and fife
Fired the living with fiercer life;
While overhead, with wild increase,
Forgetting its ancient toll of peace,
The great bell swung as ne’er before;
It seemed as it would never cease;
And every word its ardor flung
From off its jubilant iron tongue
Was, “War! War! War!”
“Who dares?” – this was the patriot’s cry,
As striding from the desk he came,-
“Come out with me, in Freedom’s name,
For her to live, for her to die?”
A hundred hands flung up reply,
A hundred voices answered, “I!”