someone who is merciful is willing to be kind to and forgive people who are in their power

"God is merciful," said the priest. “上帝是仁慈的，”神父说道。

a merciful ruler 仁慈的统治者

used to say that you are grateful for an event or situation because it stops something unpleasant

After such a long illness, her death came as a merciful release. 经受了如此漫长的病痛折磨之后，她的死算是一种幸运的解脱。