This first one describes Chillingworth and shows him to appear demonic in form.
"...there came a glare of red light out of his eyes; as if the old man's soul were on fire, and kept on smoldering duskily within his breast, until, by some casual puff of passion, it was blown into a momentary flame...Chillingworth was a striking evidence of man's faculty of transforming himself into a devil, if he will only, for a reasonable space of time, undertake a devil's office".
This one is when Pearl refers to Chillingworth as "the black man", which is another term for "the devil" - and therefore connects him to evil.
--"Come away, mother! Come away, or yonder old black man will catch you! He hath got hold of the minister already. Come away, mother or he will catch you! But he cannot catch little Pearl!"
This last quote is from the narrator, who expresses that Chillingworth has been taken over by evil tendencies.
"Calm, gentle, passionless, as he appeared, there was yet, we fear, a quiet depth of malice, hitherto latent, but active now, in this unfortunate old man, which led him to imagine a more intimate revenge than any mortal had ever wreaked upon an enemy. To make himself the one trusted friend, to whom should be confided all the fear, the remorse, the agony, the ineffectual repentance, the backward rush of sinful thoughts, expelled in vain!"