What is the theme and meter of "On being brought from Africa to America"?

In the poem "On Being Brought from Africa to America,"
Wheatley is stating that she has been redeemed. She has been enlightened as to God's
redemptive plan. She states that her soul now understands God as Saviour...Wheatley
shares that her "sable" or black race can be refined and united with God just like the
white man...

Amazingly, she was not seeking God but as
mercy would have it, he found her and now she is understanding of God and his redemptive
plan...

Wheatly clearly understands there are people who
scorn her race and she writes to give them an understanding that white men are not the
only ones who can experience God and His redemptive plan. she speaks to the white
Christians:

'Twas mercy brought me from
my Pagan
land,

Taught my
benighted soul to
understand

That
there's a God, that there's a Saviour
too:

Once I
redemption neither sought nor
knew.

Some view our
sable race with scornful
eye,

"Their colour
is a diabolic
die."

Remember, Christians, Negros,
black
as Cain,

May
be refin'd, and join th' angelic train.

The
rhyme scheme is aabb...she writes in heroic couplets throughout the poem...the theme is
physical and spiritual rescue by God...the tone is serious and meditative...the point of
view is first person meditation...Wheatley uses subtle irony in that she writes to make
her white readers feel good yet perceive how wrong they are for thinking only white
people can be Christians...