In "The Crucible," why does Elizabeth deny John's relationship with Abigail? What is the result of her denial?

Elizabeth denies that John had a relationship with Abigail because even though she has not forgiven him, he is her husband and she is a very virtuous woman and will remain loyal to her husband. 

She does not want to discuss the illicit relationship because she is not going to reveal to the court or the town that her husband is a sinner.  Puritans were very intolerant of pleasures of the flesh.  Their lives were marked by hard work and faith.  John Proctor is a very judgmental man, not given to forgiveness. So for his indiscretion to be revealed would be a public humiliation.  

Unfortunately, when John gives his testimony, he admits that he had a relationship with Abigail.  John is then accused of being a witch and conspiring with the devil.