What is the tone of the works of Rabindranath Tagore?

Although I am happy to answer this question, please know
that I think it is unfair to label ALL of the works of a particular author with one
tone.  Tone, of course, is the attitude of the author towards his or her subject.  This
being said, because Rabindranath Tagore's subject is almost always the same, then it's
fairly safe to say that his tone is usually one of spiritual
didacticism. 

Rabindranath Tagore, be it through the verse
of Gitanjali (Song of Offerings) or the intense plot of his "The
Postmaster" or the lectures revealed in The Religion of Man, always
speaks about both Eastern and Western thought, the similarities, the differences, and
how to use the spirituality (especially that of the East) to make one's life better. 
THIS is the reason why I say that the tone is general spiritual didacticism.  Because
Rabindranath Tagore had a spiritual experience (some call it "Transcendental") involving
unification with nature and God, he dedicated his life to the pursuit of sharing that
same happiness with others.  Central to his belief system is his knowledge about
everything containing at least some divinity within.  It is this knowledge (stemming
from his visions and experiences) that led to a huge burst of creativity that lasted
decades, when he produced all of his literature.

In
conclusion, I want to end with one of my very favorite quotes by Rabindranath
Tagore:

Every
child comes with the message that God is not yet discouraged of
man.

In my opinion, this sums
up the spiritual didacticism tone of Rabindranath Tagore and his works as a whole. 
Rabindranath Tagore is teaching us about spirituality and about God's kingdom ... or at
least the one "of this world."