Mr Utterson

• If he shall be Mr Hyde, i shall be Mr seek 


  The phrase "if he shall be Mr. Hyde, I shall be Mr. Seek" captures Utterson's role as the persistent seeker of truth.
• "I incline to Cain's heresy"


  Utterson expresses his belief that people should be allowed to live their lives as they choose, without judgement or interference.
• "Never lighted by a smile"

  A description of Utterson's countenance , which suggests that he is serious and doesn't smile often.
• "if ever i read Satan's signature upon a face, it is on that of your new friend"


  He is basically saying that Hyde gives of Satanic vibes.