The quote has been attributed to several people:
Plato.
Socrates.
Reverend John Watson.
Ian MacLaren.
As it turns out, Ian MacLaren is actually the pen name for the aforementioned Reverend John Watson, a Scottish author and theologian who lived the majority of his life during the second-half of the nineteenth century. He passed away in 1907 at the age of 57.
Ten years earlier, in 1897, the Reverend Watson was invited by the popular religious newspaper, the British Weekly, to submit a Christmas message.