Good Friday service is one of the most solemn, sad and holy. I've gone to Old St. Paul's for the last two years in a row and will have this hymn in my head until Sunday.
Vs. 3 gets me every time:
What language shall I borrow to thank thee, dearest friend, for this thy dying sorrow, thy pity without end? Oh, make me thine for ever! and should I fainting be, Lord, let me never, never, outlive my love for thee.