The full title of the collection is: 
"Heilige Seelen-Lust, oder Geistliche Hirten-Lieder der in ihren Jesum verliebten Psyche gesungen von Johann Angelo Silesio, Und von Herren Georgio Josepho mit außbundig schönen Melodeyen geziert / Allen liebhabenden Seelen zur Ergetzligkeit und Vermehrung ihrer heiligen Liebe / zu Lob und Ehren Gottes an Tag gegeben" 
Saintly Soul-Pleasure, or Spiritual Pastoral Songs, of the Soul that loveth Jesus, sung by Johann Angelus Silesius, and ornamented by Master George Joseph with wonderfully lovely Melodies.
To all charitable Souls for the Satisfaction and Increase of their holy Love / to the Praise and Honour of God presented.

Scheffler's poem is in eight stanzas of six lines each, with rhyme scheme ABABCC.
The shorter final line accents its content.
It is part of a 1657 collection of pastoral religious poetry, Heilige Seelen-Lust Oder geistliche Hirten-Lieder Der in ihren JESUM verliebten Psyche (Holy bliss of the soul, or: spiritual shepherd songs of Psyche who is in love with her Jesus), in which the first person (ich) is the shepherdess and Jesus the shepherd.
The original header confirm this: "Sie verspricht sich jhn biß in Tod zu lieben" (She promises herself to love him until her death).
The poetry is in the tradition to interpret the Song of Songs as referring to Jesus.

The first two stanzas are a confession of love, with seven of its twelve lines beginning "Ich will dich lieben".
The religious dimension is revealed at the end of the second stanza, referring to "Gottes Lamm" (Lamb of God).
The first line relates already to Psalm 18:2.
The third and fourth stanza refer to the themes of searching for the missed loved one from the Song of Songs.
Love is described as "spät" (late), following Augustine's Confessiones 10, 27 and 34.
It may relate to Scheffler's "late" (1653) conversion to the Catholic Church.
The fifth to seventh stanzas express thanks for "Himmelswonne" (Heavenly bliss), including erotic imagery in the seventh stanza, which is therefore sometimes omitted in hymnals.
The final stanza repeats the promise of the first, adding the motif of love for love's sake, without reward.
The full title of the collection is: 
"Heilige Seelen-Lust, oder Geistliche Hirten-Lieder der in ihren Jesum verliebten Psyche gesungen von Johann Angelo Silesio, Und von Herren Georgio Josepho mit außbundig schönen Melodeyen geziert / Allen liebhabenden Seelen zur Ergetzligkeit und Vermehrung ihrer heiligen Liebe / zu Lob und Ehren Gottes an Tag gegeben" 
Saintly Soul-Pleasure, or Spiritual Pastoral Songs, of the Soul that loveth Jesus, sung by Johann Angelus Silesius, and ornamented by Master George Joseph with wonderfully lovely Melodies. To all charitable Souls for the Satisfaction and Increase of their holy Love / to the Praise and Honour of God presented.
Scheffler's poem is in eight stanzas of six lines each, with rhyme scheme ABABCC. The shorter final line accents its content. It is part of a 1657 collection of pastoral religious poetry, Heilige Seelen-Lust Oder geistliche Hirten-Lieder Der in ihren JESUM verliebten Psyche (Holy bliss of the soul, or: spiritual shepherd songs of Psyche who is in love with her Jesus), in which the first person (ich) is the shepherdess and Jesus the shepherd. The original header confirm this: "Sie verspricht sich jhn biß in Tod zu lieben" (She promises herself to love him until her death). The poetry is in the tradition to interpret the Song of Songs as referring to Jesus.
The first two stanzas are a confession of love, with seven of its twelve lines beginning "Ich will dich lieben". The religious dimension is revealed at the end of the second stanza, referring to "Gottes Lamm" (Lamb of God). The first line relates already to Psalm 18:2. The third and fourth stanza refer to the themes of searching for the missed loved one from the Song of Songs. Love is described as "spät" (late), following Augustine's Confessiones 10, 27 and 34. It may relate to Scheffler's "late" (1653) conversion to the Catholic Church. The fifth to seventh stanzas express thanks for "Himmelswonne" (Heavenly bliss), including erotic imagery in the seventh stanza, which is therefore sometimes omitted in hymnals. The final stanza repeats the promise of the first, adding the motif of love for love's sake, without reward.
Ich will dich lieben, meine Stärke