What was the purpose of The Dialogue?

The purpose of The Dialogue by Saint Catherine of Siena, now the patron saint of Italy, is to reveal the word of God and document it for posterity, as well as to inspire and educate. The Dialogue was written during a difficult spiritual and political time (1377–1378), but it remains pertinent and applicable today.  
The Dialogue tells of an experience of ecstasy that St. Catherine experienced, during which she had the possibility to converse with God the Father.
In this dialogue, God explains and stresses how important cultivating virtue is in order to be a good Christian; virtue can be cultivated in a variety of ways, such as continuous prayer and learning the quality of obedience. He explains that the soul is connected and united to God through the incarnate Word, and those who drown their will into God's become one with god; the link between soul and divinity is fundamental in St. Catherine's work. 
Encouraged by her connection to the divine, St. Catherine makes a series of petitions to God, asking for the possibility to suffer to atone for her sins, for the reform of the Holy Church, for peace to be granted to the whole world and for a specific undisclosed case which has arisen.