The Message of Divine Mercy is that God is merciful. He is love itself poured out for us, and He wants no one to escape that merciful love.
The message is that God wants us to turn to Him with trust and repentance while it is still a time of mercy, before He comes as the just Judge. This is turning with trust to Him who is Mercy itself is the only source of peace for mankind. Turning to and imploring God’s mercy is the answer to the troubled world, there is no escaping that answer.
The essence of the Divine Mercy message and devotion is to trust in His mercy and be merciful to others.