When I've finally spoken these words I've usually exhausted all Earthly options regarding the situation I'm experiencing. And I've turned the situation over to a higher intelligence/power/spiritual authority than mine.
I don't remember ever saying these words without a heavy heart or without tears. But after they've been said I do feel a sense of Peace, and the presence and encouragement of the Higher Realms.
These few words help me to trust that there is a higher purpose to what I, or someone I care for, is experiencing. I just don't know what it is at the moment.
They help me to trust that there is a Divine Order to all situations. Even if I'm immersed in the chaos of it.
So, if you find yourself in a situation that has brought you to your knees I offer you Compassion and Love. And a most powerful prayer, "Thy Will not my will".