This poem, unusual for him as to subject matter, is prayerful indeed, beginning:
Good and great God, can I not think of thee
But it must straight my melancholy be?
Like a lot of people, it’s not his happiest moment to think of the Christian God with His reputation for justice, the poet being “laden with [his] sins,” even as he “seeks for ease.”
He describes his situation:
. . . I dare pretendTo ought but grace or aim at other end.As thou art all, so be thou all to me,
So, he turned to God, calling him “my judge, my witness, and my advocate. ”
That’s God — judge, witness, defense lawyer. A healthy concept.
Read the rest at Poetry Foundation