What does Robert Frost want to convey through the poem "Stopping by Woods on a Snowy Evening?"

"Stopping by Woods on a Snowy Evening" can be read as an allegory. Frost devotes the first three stanzas of the poem to describe the woods he comes across while he was on his way to accomplish some important task. But it's only in the final stanza, he reveals the main theme of the poem. 

He halts for the serenity and bewitching beauty of the place holds him spellbound. He lingers there for a while...

"Stopping by Woods on a Snowy Evening" can be read as an allegory. Frost devotes the first three stanzas of the poem to describe the woods he comes across while he was on his way to accomplish some important task. But it's only in the final stanza, he reveals the main theme of the poem. 

He halts for the serenity and bewitching beauty of the place holds him spellbound. He lingers there for a while pleasing himself with the peaceful joy the woods offer him in that “snowy evening.”

The snow has covered the entire place. The soft snow hangs over the trees and the lake has frozen completely. The only sound that can be heard in that uninhabited place is that of the horse’s “harness bells” and “the sweep / Of easy wind and downy flake.”

The pristine and idyllic beauty of the woods casts a spell on him making him reluctant to move on. But soon he recalls he has “promises to keep.” He ought not to linger there pleasing himself rather continue with his journey. He’s still “miles to go.”

So, we see he faces a dilemma. On the one hand he wants to prolong his stay in the woods and revel in the delight that he hasn’t found anywhere else, while on the other hand, he knows he must leave instantly to fulfill his duty.

What the poet wants to convey is, perhaps, the fact that life often comes up with attractive enticements once we have made up our mind to stop not until our goal is achieved. It makes our journey even more arduous and challenging.

The poet, too, is offered a similar enticement in the form of the beautiful woods. There’s nobody to question him or order him to leave the place. But he wouldn’t indulge in self-gratification. He would forsake this pleasure to keep his promises.