On: every psalm and song in the daily prayers uses today’s English. Off: all of them use the older “thee and thou”. Until you choose, the Songs of Zechariah, Mary and Simeon use today’s English, as most churches sing them. The Lord’s Prayer and the prayers for the dying show the form most people learned.
A remission of temporal punishment for sin, in Luther's day sold to fund building projects. The immediate occasion of the Ninety-Five Theses, though not their deepest concern.
In Doctrine — What Lutherans teach, and where it differs from neighbouring traditions.