Why am I loth to leave this earthly scene?

Why am I loth to leave this earthly scene?
How I so found it full of pleasing charms?
Some drops of joy with draughts of ill between:
Some gleams of sunshine 'mid renewing storms:
Is it departing pangs my soul alarms?
Or Death's unlovely, dreary, dark abode?
For guilt, for guilt, my terrors are in arms;
I tremble to approach an angry God,
And justly smart beneath his sin-avenging rod.

Fain would I say, "Forgive my foul offence!"
Fain promise never more to disobey;
But, should my Author health again dispense,
Again I might desert fair virtue's way:
Again in folly's path might go astray;
Again exalt the brute and sink the man;
Then how should I for heavenly mercy pray,
Who act so counter heavenly mercy's plan?
Who sin so oft have mourn'd, yet to temptation ran?

O Thou, great Governor of all below!
If I may dare a lifted eye to Thee,
Thy nod can make the tempest cease to blow,
Or still the tumult of the raging sea:
With that controlling pow'r assist ev'n me
Those headlong furious passions to confine;
For all unfit I feel my pow'rs to be,
To rule their torrent in th' allowed line;
O, aid me with Thy help, Omnipotence Divine!