Clipped from www.dcuguide.com:
History: Oaths may reflect the ring wielder's adventures, their homeworld, the cosmos, or be a battle cry. A few Green Lanterns, such as Lysandra of Zintha, chose oaths to honor their deities, and would speak it as a prayer.
[Green Lantern Vol. 2 #162]
A number of oaths, such as that of Olapet of Southern Goldstar, remain untranslatable by the power ring. Katma Tui-Stewart of Korugar did not choose to recite an oath for many years. She would remain silent while recharging her power ring, but later chose a fellow ring wielder's oath. It is not known when members of the Green Lantern Corps started the practice of reciting oaths. [Green Lantern Corps #217]
A Green Lantern might honor his/her/its predecessor, trainer, or other notable Green Lantern by adopting their oath. The most widely known oath was that of Hal Jordan of Earth, considered the greatest Green Lantern of all. Jordan's oath would be adopted by many of his fellow Green Lanterns, including most of the Green Lantern Corps of Earth. One member of that Corps, Salakk of Slyggia, chose to keep his oath, the oath spoken by Tomar-Re and Alan Scott. [Showcase #22, Green Lantern Vol. 2 #201, Green Lantern Vol. 2 #36]
Jordan's oath was composed a week after he became Green Lantern. Each line has special significance to the emerald crusader. He explained how he wrote the oath to Tom Kalmaku, keeper of the GREEN LANTERN CASEBOOK.
"In brightest day" was from a bank robbery involving a super-magnesium bomb. When the device exploded, anyone without protective eye-goggles were blinded, including Hal Jordan. He switched to his Green Lantern identity, but still could not see the bank robbers. Green Lantern used his ring as a radar device and managed to capture the criminals. A day or so later, Green Lantern followed a trio of train robbers to a network of caves in the Sierro Hills. The robbers had memorized every foot of the caves and easily eluded capture. The cave was darkened by a thick, black fog that even the power ring had trouble penetrating. Green Lantern commanded the ring to make the robbers themselves glow. Sweeping the beam around the cave, the robbers were now visible, even "in blackest night..." A break-in at Ferris Aircraft netted two burglars a safe containing a large sum of money: the company payroll. Green Lantern knew he had no time to waste. It was his duty to find the criminals, "...no evil will escape my sight..." no matter how difficult it would be. He blanketed the area surrounding Ferris Aircraft with a wide belt of radiation. When the safe was blown, Green Lantern detected the minute earth tremors which led him to the criminals. The last two lines "...let those who worship evil's might, beware my power --Green Lantern's light!" were added to make the oath rhyme.[Green Lantern Vol. 2 #10]
In later years, Jordan changed the oath slightly. The word "blackest" was replaced with "darkest." He told Kalmaku that he was becoming a bit politically correct. [Green Lantern Vol. 3 #43]
To be denied the recitation of the oath is a mark of dishonor. As seen in the case of Dalor of Timron, a Green Lantern accused of malfeasance may not speak his oath until his guilt or innocence is determined. Though the Green Lantern of Timron was cleared of charges levelled against him, he later adopted the oath of Tomar-Re, the previous ring wielder of Space Sector 2813.[Green Lantern Vol. 2 #155, 193]
The sad case of Driq of Criq shows how important the oath is to a Green Lantern. Even after his death, his ring refused to let his life force escape his body. Despite the obvious difficulties, he still managed to verbalize some thought during the charging of his power ring.[Green Lantern Vol. 2 #217]
"And I shall shed my light over dark evil,
For the dark things cannot stand the light,
the light of the Green Lantern!"
-Alan Scott, the Golden Age Green Lantern - [Green Lantern Vol. 1 #4 - Summer 1942]
I shall shed my light upon dark evil,-Alan Scott, the Golden Age Green Lantern - [Green Lantern Vol. 1 #5 - Autumn 1942]
For evil cannot stand the light of Green Lantern!"
"Let the light of the lantern-Alan Scott, the Golden Age Green Lantern - [All-American Comics #45 - December 1942]
penetrate the dark places
of ignorance and wrong,
setting all minds right
and overthrowing all servants of evil!
I shed my light upon the darkness!
Evil has no place to hide itself!
Green Lantern goes forth to conquer!"
"My rays strike the darkest corner,-Alan Scott, the Golden Age Green Lantern - [Comics Cavalcade #1, Winter, 1942]
Banishing all wickedness!"
"Let all power and triumph be mine in whatever right I do!"-Alan Scott, the Golden Age Green Lantern - [Green Lantern Vol. 1 #6 - Winter 1942-1943]
"The light of the Green Lantern-Alan Scott, the Golden Age Green Lantern - [All-American Comics #47 - February 1943]
pierces darkness and mystery,
and its radiance
will strike at the heart of evil!"
"As the green rays strike forth into darkness,-Alan Scott, the Golden Age Green Lantern - [1943, credited to Alfred Bester] and
so may all black evil be exposed and driven away!"
-Hal Jordan of Earth [Showcase #22]
"In brightest day, in blackest night,Later adopted by: Arisia, Ch'p, Guy Gardner, John Stewart, Katma Tui-Stewart, Kilowog, Quarzz Teranh, Symon Terrynce, El'Qa Sqa Zreenah
no evil shall escape my sight!
Let those who worship evil's might,
beware my power.. Green Lantern's light!"
-Evil Green Lantern's light!" Guy Gardner of Earth - [Green Lantern Vol. 2 #59, John Broome]
"On worlds afar or scenes at home,-N'Gon - [DC Comics Presents #26, Jim Starlin]
wherever the cause should make me roam,
always I vow to fight the good fight--
to combat evil with all Green Lantern's might!"
"With power present in lantern's light,-Eddore of Tront - [Tales of the Green Lantern Corps #1, Len Wein] (first of two oaths)
No force shall stay my hand this night!
Let those who do prepare to fight,
Dare no man challenge N'Gon's might!"
"From lantern comes the gift we give---Dalor of Timron - [Green Lantern Vol. 2 #155, Mike W. Barr] (interrupted before completion)
to shed light's grace on all that live!"
"I charge this ring with matchless might,-Penelops of Penelo - [Green Lantern Vol. 2 #159, Bob Rozakis]
To banish all of evil's blight.
May all my --"
"In brightest light,-Eddore of Tront - [Green Lantern Vol. 2 #160, Mike W. Barr]
in darkest sea,
all dangers will be seen by me!
While others from these dangers flee,
I shall always a Green Lantern be!"
"...power to foil evil with me instill...-Liana of M'Elu - [Green Lantern Vol. 2 #162, Kurt Busiek]
my Green Lantern vow to fulfill!"
"The cosmos through,-Lysandra of Zintha - [Green Lantern Vol. 2 #169, Jack C. Harris]
in every part,
one thing endures:
a loving heart.
Against the knaves
who'd quell this song
Green Lanterns stand,
to right the wrong!"
"As I touch this battery,-Bizarro Yellow Lantern - [DC Comics Presents #71, E. Nelson Bridwell]
flow the power into me.
Guide my hand, my heart, my soul...
make right and justice my lasting goal!
In the name of Thar...Amen!"
"In blackest day,-K'ryssma of Etrea - [Green Lantern Vol. 2 #198, Steve Englehart]
in brightest night...
huh? Why battery not charging my power ring?"
"Once there was but darkness,-The Green Man of Uxor - [Omega Men #29, Todd Klein] (interrupted before completion)
full and forever-
but then came the light,
and then the life,
and then the light of the Green Lantern--
and then myself,
to do it justice!"
"Bring light to the ring,-Flodo Span of Inner Tasnia - [Green Lantern Vol. 2 #217, Steve Englehart]
I charge thee--unveil every evil around me!
Replenish the power to--"
"Once there was but darkness,-Driq of Criq - [Green Lantern Vol. 2 #217, Steve Englehart]
full and forever--
but then came the light of the Green Lantern--
and then myself--
to do it justice!"
(since death, Driq's verbal skills are not what they used to be)
"PLUPHH!"-Rot Lop Fan of the Obsidian Deeps - [Tales of the Green Lantern Corps Annual #3, Alan Moore]
"In loudest din or hush profound,-Sinestro of Korugar - [Green Lantern Vol. 2 #222, Steve Englehart]
my ears catch evil's slightest sound.
Let those who toll out evil's knell,
beware my power: The F-Sharp Bell!"
"Let those who worship evil's might---Jack T. Chance of Garnet - [Green Lantern Corps Quarterly #1, John Ostrander]
beware my power,
the power of the Green Lantern!"
"You who are wicked, evil, and mean---Barin - [Green Lantern Corps Quarterly #7, James Robinson]
I'm the nastiest creep you've *ever* seen!
Come one, come all; put up a fight;
I'll pound your butts with Green Lantern's light.
"In this place of black and grey and dark...
the green shall be my light, my hope, my strength.
All that is good is all I defend.
I shall not falter."
-Perdoo of Qualar IV - [Green Lantern Annual #5, Len Wein]
"When day is bright...-Medphyll of J586 - [Swamp Thing #61, Alan Moore]
...or is it night?
...something or other
will escape my sight...
...let those who...who...
Let all those looking for a fight...
...something something something...
Green Lantern's light."
"In forest dark or glade be ferned,-Anya Savenlovich of Earth - [Green Lantern: The New Corps #2 - April 1999, Chuck Dixon]
no blade of grass shall go unturned.
Let those that have the daylight spurned,
tread not where this green lamp has burned"
"For social justice-Garl Rathbone - [Green Lantern: The New Corps #2 - April 1999, Chuck Dixon]
and the future of
"uh...-Sool of Waystation - [Green Lantern: The New Corps #2 - April 1999, Chuck Dixon]
I swear only to do the right thing and not hurt anyone...
who doesn't deserve it already."
"To bring order to chaos.-Hammeroon - [Green Lantern: The New Corps #2 - April 1999, Chuck Dixon]
Law to the lawless
and light to the shadow"
"To protect the weak-Abin Sur of Ungara - [Legends of the DC Universe #21 - April 1999, Steven Grant]
and have the guts
to hunt down the bad guys
and kick their -"
"I will fear no evil,-Teen Lantern Corps - [Green Lantern: Circle of Fire #1 - 2000, Brian Vaughn]
for I illuminate the darkness
with the light of justice --
the justice of the Green Lantern!"
"That the ring's light-Kho of Khundia - [Wonder Woman Vol. 3 #19 - June 2008, Gail Simone]
will always be shared
and that no evildoer
shall ever be spared"
"Against dishonor and traitor’s flight-Sodam Yat of Daxam, 31st Century Guardian of the Universe - [Final Crisis: Legion of Three Worlds #3 - 2009, Geoff Johns]
I stand beside my clan to fight
With dying breath I claw and bite
Beware my power
Green Lantern’s light!"
"In brightest day-The oath of Sinestro - [Green Lantern/Sinestro Corps Special #1, August 2007, Geoff Johns]
through blackest night!
No other corps shall spread its light!
Let those who try to stop what’s right
burn like my power
Green Lantern's light!"
"In blackest day...-Sinestro Corps - [Green Lantern Vol. 4 #21, September 2007 – Geoff Johns]
in brightest night...
beware your fears made into light...
let those who try to stop what’s right –
Burn like my power –
"In blackest day, in brightest night!-Red Lantern Corps - [Green Lantern Vol. 4 #32, August 2008 – Geoff Johns]
Beware your fears made into light.
Let those who try to stop what’s right –
Burn like his power –
"With blood and rage of crimson red-Blue Lantern Corps - [Green Lantern Vol. 4 #36, January 2009 – Geoff Johns]
Ripped from a corps so freshly dead
Together with our hellish hate
We’ll burn you all, that is your fate!
"In fearful day-Star Sapphires - [Green Lantern Vol. 4 #38, March 2009 – Geoff Johns]
In raging night
With strong hearts full
Our souls ignite
When all seems lost
In the war of light
Look to the Stars
For hope burns bright!
"For hearts long lostFun Image:
And full of fright
For those alone in Blackest Night
Accept our ring
And join our fight
Love conquers all
With violet light!