Why does the sexton agree to let the narrator see the pit?

The sexton agrees to let the narrator see the pit in part because they were previously acquainted, and in part because he made a satisfactory argument.

I got admittance into the churchyard by being acquainted with the sexton who attended; who, though he did not refuse me at all, yet earnestly persuaded me not to go, telling me very seriously (for he was a good, religious, and sensible man) that it was indeed their business and duty to venture, and to run all hazards, and that in it they might hope to be preserved; but that I had no apparent call to it but my own curiosity, which, he said, he believed I would not pretend was sufficient to justify my running that hazard. I told him I had been pressed in my mind to go, and that perhaps it might be an instructing sight, that might not be without its uses. 'Nay,' says the good man, 'if you will venture upon that score, name of God go in; for, depend upon it, 'twill be a sermon to you, it may be, the best that ever you heard in your life. 'Tis a speaking sight,' says he, 'and has a voice with it, and a loud one, to call us all to repentance'; and with that he opened the door and said, 'Go, if you will.'