A house divided against itself cannot stand. The "house" that Lincoln mentions is a reference to

And the scribes which came down from Jerusalem said, He hath Beelzebub, and by the prince of the devils casteth he out devils. 23And he called them unto him, and said unto them in parables, How can Satan cast out Satan? 24And if a kingdom be divided against itself, that kingdom cannot stand. 25And if a house be divided against itself, that house cannot stand. 26And if Satan rise up against himself, and be divided, he cannot stand, but hath an end. 27No man can enter into a strong man's house, and spoil his goods, except he will first bind the strong man; and then he will spoil his house. 28Verily I say unto you, All sins shall be forgiven unto the sons of men, and blasphemies wherewith soever they shall blaspheme: Full scripture from the bible.

The phrase is derived from a verse in the Bible (Mark 3, verse 25)