Chazal tell us that
G-d leads a person on the path he desires. *
Makkot 10b
They also say
Everything is in the hands of Heaven, except fear of Heaven (aka desire).
Berachot 33b
From these (and more), we learn the significance of desire — and that it’s the root cause of our behavior and actions. (Which makes total sense because, in general, we do what we desire.)
In the book Inner Work the Baal HaSulam is quoted as saying:
Sin itself is the punishment.
Page 67
Fascinatingly, a sin is actually the result or punishment for desires that are not in line with G-d’s will, and the sin itself, quite counterintuitive is for the purpose of correcting our desires through teshuvah.
Sins are like red flags of what we need to work on to live life in line properly. They are actually a great gift for spiritual growth.
* The Maharsh’a says that from every worthy desire, an angel is created. Hence, the more good desires a person has, the more angels he creates. These angels are G-d’s messengers who are actually leading a person according to their desires.
Yitzhak Sasson 