I know that most Americans associate the phrase with Lincoln, and for good reason, because he used it to great effect in the Lincoln Douglas debates. But Lincoln was quoting someone else.
One of Lincoln's favorite sources was the Bible, that indispensable basis of English literature. The quote is actually from Jesus, in the Gospel according to Matthew, chapter 12:
22. Then was brought unto him one possessed with a devil, blind, and dumb: and he healed him, insomuch that the blind and dumb both spake and saw. 23 And all the people were amazed, and said, Is not this the son of David? 24 But when the Pharisees heard [it], they said, This [fellow] doth not cast out devils, but by Beelzebub the prince of the devils. 25 And Jesus knew their thoughts, and said unto them, Every kingdom divided against itself is brought to desolation; and every city or house divided against itself shall not stand: 26 And if Satan cast out Satan, he is divided against himself; how shall then his kingdom stand? 27 And if I by Beelzebub cast out devils, by whom do your children cast [them] out? therefore they shall be your judges. 28 But if I cast out devils by the Spirit of God, then the kingdom of God is come unto you. 29 Or else how can one enter into a strong man's house, and spoil his goods, except he first bind the strong man? and then he will spoil his house. 30 He that is not with me is against me; and he that gathereth not with me scattereth abroad. 31 Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy [against] the [Holy] Ghost shall not be forgiven unto men. 32 And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the [world] to come. 33 Either make the tree good, and his fruit good; or else make the tree corrupt, and his fruit corrupt: for the tree is known by [his] fruit. 34 O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. 35 A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things. 36 But I say unto you, That every idle word that men shall speak, they shall give account thereof in the day of judgment. 37 For by thy words thou shalt be justified, and by thy words thou shalt be condemned.
I quote from the King James version, not because I think it is the best translation, but because it is the literary version in English, and this is about allusion in English, not about theology.
What really shocks me is that many of the Congressional representatives who think they are quoting Lincoln, not realizing that he was quoting Jesus, think they are Bible-believing Christians and that the United States is supposed to be a Christian nation based on the Bible. Have they even read the Bible? They certainly don't know it very well. By their words in the Congress they shall be judged, and by their words in Congress they shall be condemned.