While I've never associated the Puritans with Christian mysticism, I was recently exposed to the poetry of Edward Taylor and learned to think otherwise. Beautiful poetry, remarkably reminiscent of previous writers of his mode. There is a lot of great depth in his poetry, though it must be read carefully and some times before fully understood and appreciated. Here is a taste:

Meditation No.1

What Love is this of thine, that Cannot bee
In thine Infinity, O Lord, Confinde,
Unless it in thy very Person see,
Infinity, and Finity Conjoyn'd?
What hath thy Godhead, as not satisfide
Marri'de our Manhood, making it its Bride?

Oh, Matchless Love! filling Heaven to the brim!
O're running it: all running o're beside
This World! Nay Overflowing Hell; wherein
For thine Elect, there rose a mighty Tide!
That there our Veans might through thy Person bleed,
To quench those flames, that else would on us feed.

Oh! that thy Love might overflow my Heart!
To fire the same with Love: for Love I would.
But oh! my streight'ned Breast! my Lifeless Sparke!
My Fireless Flame! What Chilly Love, and Cold?
In measure small! In Manner Chilly! See.
Lord blow the Coal: Thy Love Enflame in mee.

A portion of Meditation No. 35:

Oh, that the Sweets of all these Windings, spouse
Might, and these Influences streight, and Cross,
Upon my Soule, to make thy Shine breake out
That Grace might in get and get out my dross!
My Soule up locks then in this Clod of Dust
Would lock up in't all Heavenly Joyes most just.

But oh! thy Wisdom, Lord! thy Grace! thy Praise!
Open mine Eyes to see the same aright.
Take off their film, my Sins, and let the Rayes
Of thy bright Glory on my peepholes light.
I fain would love and better love thee should,
If 'fore me thou thy Loveliness unfold.

Lord, Cleare my Sight, thy Glory then out dart.
And let thy Rayes beame Glory in mine eye
And stick thy Loveliness upon my heart,
Make me the Couch on which thy Love doth ly.
Lord make my heart thy bed, thy heart make mine.
Thy Love bed in my heart, bed mine in thine.