If you describe an event or situation as merciful, you mean that it is a good thing, especially because it stops someone's suffering or discomfort. Eventually the session came to a merciful end
characterized by mercy, and compassion; "compassionate toward disadvantaged people"; "kind to animals"; "a humane judge"
showing or giving mercy; "sought merciful treatment for the captives"; "a merciful god"
If you describe God or a person in a position of authority as merciful, you mean that they show kindness and forgiveness to people. We can only hope the court is merciful
used conventionally of royalty and high nobility; "our merciful king" showing or giving mercy; "sought merciful treatment for the captives"; "a merciful god