Tennyson's poem "The Deserted House" can be critically analyzed in different ways depending on the interpretation of the reader. This being said, know that this is simply my own understanding of the poem and its meaning.
This poem speaks to life on earth and death. The house in the first four stanzas represent the body that one leaves behind when they die. Upon death, the body is a simple shell. The body is then buried to return to the dust from which it was first created (Biblical reference to the giving of life to Adam). One sees this in the following lines:
Come away: no more of mirth
Is here or merry-making sound.
The house was builded of the earth,
And shall fall again to ground.
The final stanza of the poem refers to the position man will take once he is taken to heaven. It is in Heaven that one finds the "city glorious".
The poem simply speaks to the fact that once man dies he loses "life and thought". He can no longer light the body he once possessed and must move on to the afterlife where he can find the true peace.