O Jesus Christ, True Light of God

What: This hymn is, I think, an translation by a Reverend John C. Kunze and is found in the very first English Lutheran hymnal, published in 1795 in New York. The full title of the book is "A Hymn and Prayer-Book for the Use of Such Lutheran Churches as Use the English Language." The book is quite a gem for a few reasons, including this hymn.
The translation in common use today is O Christ, Our True and Only Light.
Who: Johann Heermann was a great Lutheran hymnwriter in the 1600's. His best-known hymn is "Ah, Dearest Jesus, What Law Hast Thou Broken?"
Changes: I only changed "dumb" to "mute."
Tune: the proper tune is O JESU CHRISTE, WAHRES LICHT, LSB 839.

O Jesus Christ, true light of God,

Enlighten such as know Thee not

And bring them unto Thy sheepfold,

Thereby to save their precious soul.

Replenish with Thy ray of grace

The wandering erroneous race

And such who're tempted secretly

To b'lieve that which is treachery.

And what else has eloped from Thee,

That seek with grace and constancy.

All wounded consciences so heal

That they show but for heav'n their zeal.

To all deaf grant an open ear;

The mute an utt'rance without fear;

Freedom to such who would confess

Their faith concerning righteousness.

Beguiléd souls do undeceive;

Bring all back who mean Thee to leave;

Them who are scattered congregate;

Convince those in a doubtful state.

Then, Lord, due praises shall be giv'n,

On earth below, above in heav'n,

By all of Thy redeeméd race,

To Thee for all Thy love and grace.

O Jesu Christe, wahres Licht
Johann Heermann
Tr. John C. Kunze, alt.