In the first stanza of the poem the speaker asks the guide how long the journey up the hill will take. The guide tells the speaker that the journey will take "from morn to night." In the second stanza the speaker asks the guide if there is anywhere for her to rest once she reaches the top of the hill, and the guide assures her that there is an inn that she "cannot miss."
In the third stanza the speaker asks the guide how she will gain admittance to the inn, and the guide says that there will be people already there to let her in. In the fourth and final stanza the guide tells the speaker that she will find "comfort" at the inn.
The inn that the guide describes to the speaker represents heaven, and the hill that the speaker walks up represents the speaker's life on earth. The meaning of the poem is that there is a heaven waiting for everybody at the end of their lives. If we understand the poem in this sense, then we can perhaps refine our understanding as to the identities of the speaker and the guide. The speaker is perhaps a Christian who is anxious about what will happen to her after her death, and the guide is perhaps an angel or even the voice of God trying to reassure the speaker.