“Such pendent tenor I pursue,
“And keep both worlds alike, in view,
“Serve both in turn, and, nothing loath,
“Secure an interest thus in both.

The first canto was agreeing with the undertaking of digging for gold. At the end of the poem the Deacon partakes in a plan to secure his wealth; another future raid like the gallant pirates (mentioning Captain Kidd). The race for the Golden Prize is on and it continues in his second canto:

When all arrangements were complete,
It was agreed next morn to meet,
And all retired it dream that night
Of old doubloons and ducats bright.

At the end of the poem Fenerty is asking why they did it in the first place. He saw the whole thing as a test; one which he failed. It's a test of faith, and the real treasure in the Kingdom of Heaven.