What are Mr.Dimmesdale's many sins?

1) Dimmesdale committed adultery with Hester.

2) Dimmesdale fathered a child out of wedlock, even worse, he didn't claim fatherhood.

3) Dimmesdale does not adhere to what he preaches; he is a hypocrite.

4) Dimmesdale's actions are governed by pride (sin)

5) He bears false witness.

Note, his sins according to the Puritan church would be adultery, bearing false witness, and of course..... pride.