The Divine Mercy devotion seems pretty simple but is really deep theology about the nature of God and the His relationship with us.
Don't feel bad if your knowledge of the Divine Mercy is limited to just the chaplet. Knowing and regularly praying the chaplet is a fine place to start. Really, you could devote your whole life to learning more about the Divine Mercy and still not “know it all”.
Listen to my interview with Vinny Flynn, one of the foremost experts on the devotion, as we discuss what Divine Mercy is all about.