What does this hymn mean?

I've heard the story of the man who wrote this hymn. I can't exactly recall his name, but he wrote this after his wife and child (i believe it was a daughter) were killed in some sort of accident (i believe it was a shipwreck). Through his mourning thoughts, he penned this hymn. It was a way of saying, although everything i love in this world has been taken from me and Satan is telling me to do bad things to "heal" my pain, I trust in God and Christ because although there is pain, I know there is a plan for me at the end and I'll see them again, so it is well with my soul.