This text comes from The Complete Poetical Works of John Greenleaf Whittier, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
At morn I prayed, “I fain would see
How Three are One, and One is Three;
Read the dark riddle unto me.”
I wandered forth, the sun and air
I saw bestowed with equal care
On good and evil, foul and fair.
No partial favor dropped the rain;
Alike the righteous and profane
Rejoiced above their heading grain.
And my heart murmured, “Is it meet
That blindfold Nature thus should treat
With equal hand the tares and wheat?”
A presence melted through my mood,—
A warmth, a light, a sense of good,
Like sunshine through a winter wood.
I saw that presence, mailed complete
In her white innocence, pause to greet
A fallen sister of the street.
Upon her bosom snowy pure
The lost one clung, as if secure
From inward guilt or outward lure.
“Beware!” I said; “in this I see
No gain to her, but loss to thee:
Who touches pitch defiled must be.”
I passed the haunts of shame and sin,
And a voice whispered, “Who therein
Shall these lost souls to Heaven’s peace win?
“Who there shall hope and health dispense,
And lift the ladder up from thence
Whose rounds are prayers of penitence?”
I said, “No higher life they know;
These earth-worms love to have it so.
Who stoops to raise them sinks as low.”
That night with painful care I read
What Hippo’s saint and Calvin said;
The living seeking to the dead!
In vain I turned, in weary quest,
Old pages, where (God give them rest!)
The poor creed-mongers dreamed and guessed.
And still I prayed, “Lord, let me see
How Three are One, and One is Three;
Read the dark riddle unto me!”
Then something whispered, “Dost thou pray
For what thou hast? This very day
The Holy Three have crossed thy way.
“Did not the gifts of sun and air
To good and ill alike declare
The all-compassionate Father’s care?
“In the white soul that stooped to raise
The lost one from her evil ways,
Thou saw’st the Christ, whom angels praise!
“A bodiless Divinity,
The still small Voice that spake to thee
Was the Holy Spirit’s mystery!
“O blind of sight, of faith how small!
Father, and Son, and Holy Call;
This day thou hast denied them all!
“Revealed in love and sacrifice,
The Holiest passed before thine eyes,
One and the same, in threefold guise.
“The equal Father in rain and sun,
His Christ in the good to evil done,
His Voice in thy soul;—and the Three are One!”
I shut my grave Aquinas fast;
The monkish gloss of ages past,
The schoolman’s creed aside I cast.
And my heart answered, “Lord, I see
How Three are One, and One is Three;
Thy riddle hath been read to me!”