The speaker of this poem really, truly, badly wants to connect with God. The divine is very important to this guy. What's more, we can assume that this speaker was at some point a pretty vain poet. After all, in line 6 he refers to his vanity, which "dies in shame before thy sight." What this means is that the speaker recognizes that, at one point, he was maybe too full of himself and too proud of his poetic abilities. He thought he was a darn good poet. But this vanity didn't lead him to God. On the contrary, it's a pretty safe guess that it led him away from God (which is why he's now changing his tune in "Song VII"—see what we did there?). This poem also reflects the speaker's new-found humility. He's become a humble guy, because he realizes that doing so, and embracing simplicity, will be the only way he's able to connect with the Man Upstairs: God.